[syntax-errors] Star annotations before Python 3.11 (#16545)
Summary
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This is closely related to (and stacked on)
https://github.com/astral-sh/ruff/pull/16544 and detects star
annotations in function definitions.
I initially called the variant `StarExpressionInAnnotation` to mirror
`StarExpressionInIndex`, but I realized it's not really a "star
expression" in this position and renamed it. `StarAnnotation` seems in
line with the PEP.
Test Plan
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Two new inline tests. It looked like there was pretty good existing
coverage of this syntax, so I just added simple examples to test the
version cutoff.
