Use consistent diagnostic messages in augmented assignment inference

[charliermarsh]

No description provided.

[github-actions]

ruff-ecosystem results

Linter (stable)

ℹ️ ecosystem check encountered linter errors. (no lint changes; 1 project error)

pypa/setuptools (error)

ruff failed
  Cause: Failed to parse /home/runner/work/ruff/ruff/checkouts/pypa:setuptools/ruff.toml
  Cause: TOML parse error at line 1, column 11
  |
1 | include = "pyproject.toml"
  |           ^^^^^^^^^^^^^^^^
invalid type: string "pyproject.toml", expected a sequence

Linter (preview)

ℹ️ ecosystem check encountered linter errors. (no lint changes; 1 project error)

pypa/setuptools (error)

ruff check --no-cache --exit-zero --ignore RUF9 --output-format concise --preview

ruff failed
  Cause: Failed to parse /home/runner/work/ruff/ruff/checkouts/pypa:setuptools/ruff.toml
  Cause: TOML parse error at line 1, column 11
  |
1 | include = "pyproject.toml"
  |           ^^^^^^^^^^^^^^^^
invalid type: string "pyproject.toml", expected a sequence