fix AttributeError crash when using --import-mode=importlib

[dongfangtianyu]

closes #13026 .

• Include new tests or update existing tests when applicable.
• Allow maintainers to push and squash when merging my commits.
• Create a new changelog file in the changelog folder.

Only parent modules with the __path__ attribute can be used by the find_spec function, and most of the standard library does not meet this condition.

https://github.com/python/cpython/blob/3.9/Lib/importlib/_bootstrap_external.py#L1223

   def _find_parent_path_names(self):
        """Returns a tuple of (parent-module-name, parent-path-attr-name)"""
        parent, dot, me = self._name.rpartition('.')
        if dot == '':
            # This is a top-level module. sys.path contains the parent path.
            return 'sys', 'path'
        # Not a top-level module. parent-module.__path__ contains the
        #  parent path.
        return parent, '__path__'

So this PR adds a condition check.

[nicoddemus]

Thanks @dongfangtianyu for investigating it and opening a fix so quickly!

Left some small comments, can you take a look?

[nicoddemus]

Thanks!

[patchback]

Backport to 8.3.x: 💚 backport PR created

✅ Backport PR branch: patchback/backports/8.3.x/8cff12865691b14b4bce70e0e304524619be385d/pr-13029

Backported as #13037

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