unittest.case: Further stub improvements

[AlexWaygood]

Fixes several things I noticed while preparing #8066.

• Use object instead of Any where literally any argument can be safely passed in.
• Where the runtime uses assignments for method aliases, do the same thing in the stub.
• Give a more precise type for assertGreater, assertLess, assertGreaterEqual and assertLessEqual.
• Correct the outdated type for assert(Not)IsInstance.

[AlexWaygood]

Diff from mypy_primer, showing the effect of this PR on open source code:

tornado (https://github.com/tornadoweb/tornado)
+ tornado/test/httpclient_test.py:693: error: Argument 1 to "assertGreaterEqual" of "TestCase" has incompatible type "Optional[float]"; expected "Union[SupportsDunderGE, SupportsDunderLE]"
+ tornado/test/httpclient_test.py:694: error: Argument 1 to "assertLess" of "TestCase" has incompatible type "Optional[float]"; expected "Union[SupportsDunderLT, SupportsDunderGT]"

psycopg (https://github.com/psycopg/psycopg)
+ tests/test_psycopg_dbapi20.py:43: error: Unused "type: ignore" comment
+ tests/test_psycopg_dbapi20.py:44: error: Unused "type: ignore" comment

These all look good to me.

• tornado source code here: https://github.com/tornadoweb/tornado/blob/4470d6927a598b2d8e7aaf14398ab7ca5b0ed5c6/tornado/test/httpclient_test.py#L693-L694. You can see here that request_time can clearly be None, at least according to the information mypy's privy to: https://github.com/tornadoweb/tornado/blob/4470d6927a598b2d8e7aaf14398ab7ca5b0ed5c6/tornado/httpclient.py#L668.
• psycopg source code here: https://github.com/psycopg/psycopg/blob/3acc1d2136a7a7b0276c53c23d789cc3a0b8dd6f/tests/test_psycopg_dbapi20.py#L43-L44

[github-actions]

Diff from mypy_primer, showing the effect of this PR on open source code:

poetry (https://github.com/python-poetry/poetry)
- src/poetry/packages/locker.py:316: error: Returning Any from function declared to return "Union[SupportsDunderLT, SupportsDunderGT]"  [no-any-return]
+ src/poetry/packages/locker.py:316: error: Returning Any from function declared to return "Union[SupportsDunderLT[Any], SupportsDunderGT[Any]]"  [no-any-return]
- src/poetry/packages/locker.py:508: error: Returning Any from function declared to return "Union[SupportsDunderLT, SupportsDunderGT]"  [no-any-return]
+ src/poetry/packages/locker.py:508: error: Returning Any from function declared to return "Union[SupportsDunderLT[Any], SupportsDunderGT[Any]]"  [no-any-return]
- src/poetry/puzzle/solver.py:138: error: Returning Any from function declared to return "Union[SupportsDunderLT, SupportsDunderGT]"  [no-any-return]
+ src/poetry/puzzle/solver.py:138: error: Returning Any from function declared to return "Union[SupportsDunderLT[Any], SupportsDunderGT[Any]]"  [no-any-return]
- src/poetry/console/commands/show.py:395: error: Returning Any from function declared to return "Union[SupportsDunderLT, SupportsDunderGT]"  [no-any-return]
+ src/poetry/console/commands/show.py:395: error: Returning Any from function declared to return "Union[SupportsDunderLT[Any], SupportsDunderGT[Any]]"  [no-any-return]
- src/poetry/console/commands/show.py:439: error: Returning Any from function declared to return "Union[SupportsDunderLT, SupportsDunderGT]"  [no-any-return]
+ src/poetry/console/commands/show.py:439: error: Returning Any from function declared to return "Union[SupportsDunderLT[Any], SupportsDunderGT[Any]]"  [no-any-return]

freqtrade (https://github.com/freqtrade/freqtrade)
- freqtrade/persistence/pairlock_middleware.py:90: error: Argument "key" to "sorted" has incompatible type "Callable[[PairLock], Column]"; expected "Callable[[PairLock], Union[SupportsDunderLT, SupportsDunderGT]]"
+ freqtrade/persistence/pairlock_middleware.py:90: error: Argument "key" to "sorted" has incompatible type "Callable[[PairLock], Column]"; expected "Callable[[PairLock], Union[SupportsDunderLT[Any], SupportsDunderGT[Any]]]"
- freqtrade/persistence/pairlock_middleware.py:90: error: Incompatible return value type (got "Column", expected "Union[SupportsDunderLT, SupportsDunderGT]")
+ freqtrade/persistence/pairlock_middleware.py:90: error: Incompatible return value type (got "Column", expected "Union[SupportsDunderLT[Any], SupportsDunderGT[Any]]")

core (https://github.com/home-assistant/core)
- homeassistant/components/zwave_js/device_condition.py:225: error: Returning Any from function declared to return "Union[SupportsDunderLT, SupportsDunderGT]"  [no-any-return]
+ homeassistant/components/zwave_js/device_condition.py:225: error: Returning Any from function declared to return "Union[SupportsDunderLT[Any], SupportsDunderGT[Any]]"  [no-any-return]
- homeassistant/components/zwave_js/device_action.py:330: error: Returning Any from function declared to return "Union[SupportsDunderLT, SupportsDunderGT]"  [no-any-return]
+ homeassistant/components/zwave_js/device_action.py:330: error: Returning Any from function declared to return "Union[SupportsDunderLT[Any], SupportsDunderGT[Any]]"  [no-any-return]
- homeassistant/components/zwave_js/device_trigger.py:538: error: Returning Any from function declared to return "Union[SupportsDunderLT, SupportsDunderGT]"  [no-any-return]
+ homeassistant/components/zwave_js/device_trigger.py:538: error: Returning Any from function declared to return "Union[SupportsDunderLT[Any], SupportsDunderGT[Any]]"  [no-any-return]

tornado (https://github.com/tornadoweb/tornado)
+ tornado/test/httpclient_test.py:693: error: Argument 1 to "assertGreaterEqual" of "TestCase" has incompatible type "Optional[float]"; expected "SupportsDunderGE[int]"
+ tornado/test/httpclient_test.py:694: error: Argument 1 to "assertLess" of "TestCase" has incompatible type "Optional[float]"; expected "SupportsDunderLT[float]"

streamlit (https://github.com/streamlit/streamlit)
- lib/tests/streamlit/watcher/local_sources_watcher_test.py:375:47: error: Returning Any from function declared to return "Union[SupportsDunderLT, SupportsDunderGT]"  [no-any-return]
+ lib/tests/streamlit/watcher/local_sources_watcher_test.py:375:47: error: Returning Any from function declared to return "Union[SupportsDunderLT[Any], SupportsDunderGT[Any]]"  [no-any-return]

paasta (https://github.com/yelp/paasta)
- paasta_tools/metrics/metastatus_lib.py:672: error: Argument "key" to "sorted" has incompatible type "Callable[[Any], Sequence[Tuple[str, str]]]"; expected "Callable[[_SlaveT], Union[SupportsDunderLT, SupportsDunderGT]]"
+ paasta_tools/metrics/metastatus_lib.py:672: error: Argument "key" to "sorted" has incompatible type "Callable[[Any], Sequence[Tuple[str, str]]]"; expected "Callable[[_SlaveT], Union[SupportsDunderLT[Any], SupportsDunderGT[Any]]]"
- paasta_tools/metrics/metastatus_lib.py:672: error: Argument "key" to "sorted" has incompatible type "Callable[[Any], Sequence[Tuple[str, str]]]"; expected "Callable[[Any], Union[SupportsDunderLT, SupportsDunderGT]]"
+ paasta_tools/metrics/metastatus_lib.py:672: error: Argument "key" to "sorted" has incompatible type "Callable[[Any], Sequence[Tuple[str, str]]]"; expected "Callable[[Any], Union[SupportsDunderLT[Any], SupportsDunderGT[Any]]]"

psycopg (https://github.com/psycopg/psycopg)
+ tests/test_psycopg_dbapi20.py:43: error: Unused "type: ignore" comment
+ tests/test_psycopg_dbapi20.py:44: error: Unused "type: ignore" comment

[srittau]

Thanks!