Minor grammatical issue in `generics_syntax_infer_variance` non-conformance message

[nathanjmcdougall]

typing/conformance/results/mypy/generics_syntax_infer_variance.toml

Line 3 in 21b0785

Type parameter syntax not yet support.

Should be not yet supported. rather than not yet support.

[JelleZijlstra]

For minor wording changes, please just submit a PR.