Remove selenium stubs

[srittau]

Closes: #7381

[AlexWaygood]

Whoosh, look at 'em go

[github-actions]

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

bokeh (https://github.com/bokeh/bokeh)
- src/bokeh/io/webdriver.py:66: note: ... from here:
- src/bokeh/io/webdriver.py:66: note: In module imported here:
+ src/typings/selenium/webdriver/firefox/webdriver.pyi:1:1: error: Cannot find implementation or library stub for module named "selenium.webdriver.firefox.service"  [import]
+ src/typings/selenium/webdriver/firefox/webdriver.pyi: note: In member "__init__" of class "WebDriver":
+ src/typings/selenium/webdriver/firefox/webdriver.pyi:7:5: error: Argument 2 to "__init__" becomes "Optional[Any]" due to an unfollowed import  [no-any-unimported]
+ src/bokeh/io/webdriver.py:66:1: error: Cannot find implementation or library stub for module named "selenium.webdriver.firefox.service"  [import]
- src/bokeh/io/webdriver.py: note: In function "create_firefox_webdriver":
- src/bokeh/io/webdriver.py:69:15: error: Missing positional argument "executable_path" in call to "Service"  [call-arg]

[AlexWaygood]

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

bokeh (https://github.com/bokeh/bokeh)
- src/bokeh/io/webdriver.py:66: note: ... from here:
- src/bokeh/io/webdriver.py:66: note: In module imported here:
+ src/typings/selenium/webdriver/firefox/webdriver.pyi:1:1: error: Cannot find implementation or library stub for module named "selenium.webdriver.firefox.service"  [import]
+ src/typings/selenium/webdriver/firefox/webdriver.pyi: note: In member "__init__" of class "WebDriver":
+ src/typings/selenium/webdriver/firefox/webdriver.pyi:7:5: error: Argument 2 to "__init__" becomes "Optional[Any]" due to an unfollowed import  [no-any-unimported]
+ src/bokeh/io/webdriver.py:66:1: error: Cannot find implementation or library stub for module named "selenium.webdriver.firefox.service"  [import]
- src/bokeh/io/webdriver.py: note: In function "create_firefox_webdriver":
- src/bokeh/io/webdriver.py:69:15: error: Missing positional argument "executable_path" in call to "Service"  [call-arg]

I think this diff is just because mypy_primer doesn't install selenium before checking bokeh: https://github.com/hauntsaninja/mypy_primer/blob/master/mypy_primer.py#L1650

[AlexWaygood]

(I've filed hauntsaninja/mypy_primer#44)