Do not count attribute docstrings for WPS226

[vyhuholl]

I have made things!

WPS226 still counted PEP 258 attribute docstrings after #3804. Four class attributes sharing one:

attr_doc.py:3:5: WPS226 Found string literal over-use: 'Some field docs.' 4 > 3

Same reasoning as #3803. The string documents the assignment above it, so moving it into a named constant would stop it from being documentation.

is_doc_string_value() accepted exactly one position, body[0] of the nearest module, class or function. It now accepts a second, and the lookup moved into a helper:

def _is_doc_string_place(body, statement) -> bool:
    """Docstrings open a definition's body or follow an assignment."""
    if body[0] is statement:
        return True
    return any(
        current is statement and isinstance(previous, AssignNodes)
        for previous, current in itertools.pairwise(body)
    )

AssignNodes is the existing (ast.Assign, ast.AnnAssign) tuple, so first = 1, second: int = 2 and a bare third: int all work. I left ast.AugAssign out, since count += 1 followed by a string isn't documenting anything.

The search stays inside the context's own body. self.third = 3 in __init__ is covered, because the context there is the method. A string after an assignment nested inside an if still counts, same as before, and so does one that follows anything other than an assignment. Both have tests.

One thing that looks odd in the diff: is_doc_string_value() now ends with context is not None and _is_doc_string_place(...) instead of an early return. Writing it as if context is None: return False drops coverage below 100%, because get_context() returns None only for the module node itself, and that can never be a docstring statement.

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• I have read and agree to the AI Policy, removed any "Co-Authored-By" lines attributing coding agents, and manually reviewed the final result

Checklist

• I have double checked that there are no unrelated changes in this pull request (old patches, accidental config files, etc)
• I have created at least one test case for the changes I have made
• I have updated the documentation for the changes I have made
• I have added my changes to the CHANGELOG.md

Related issues

Closes #3805

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 100.00%. Comparing base (b841755) to head (019a1ea).

Additional details and impacted files

@@            Coverage Diff            @@
##            master     #3806   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files          374       374           
  Lines        12682     12708   +26     
  Branches       875       879    +4     
=========================================
+ Hits         12682     12708   +26     

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[sobolevn]

Please, also test type-aliases, see https://discuss.python.org/t/docstrings-for-type-aliases/108901 for the context

[sobolevn]

🤔

[vyhuholl]

Sorry, that was comment for the wrong PR. 🙈

[sobolevn]

Now this seems correct, thank you :)

[sobolevn]

Please, don't forget about new rule request for docstring positions :)