[syntax-errors] Reimplement PLE0118 (#17135)
Summary
--
This PR reimplements
[load-before-global-declaration
(PLE0118)](https://docs.astral.sh/ruff/rules/load-before-global-declaration/)
as a semantic syntax error.
I added a `global` method to the `SemanticSyntaxContext` trait to make
this very easy, at least in ruff. Does red-knot have something similar?
If this approach will also work in red-knot, I think some of the other
PLE rules are also compile-time errors in CPython, PLE0117 in
particular. 0115 and 0116 also mention `SyntaxError`s in their docs, but
I haven't confirmed them in the REPL yet.
Test Plan
--
Existing linter tests for PLE0118. I think this actually can't be tested
very easily in an inline test because the `TestContext` doesn't have a
real way to track globals.
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Co-authored-by: Micha Reiser <micha@reiser.io>
