Emit better syntax error for unicode prefix

[dylwil3]

Currently we get:

❯ echo 'uf"a"' | ruff check --output-format concise -
-:1:3: SyntaxError: Simple statements must be separated by newlines or semicolons
Found 1 error.

but ideally we would get the more informative (as of Python 3.14):

>>> uf"a"
  File "<python-input-0>", line 1
    uf"a"
    ^^
SyntaxError: 'u' and 'f' prefixes are incompatible

and similarly for t-strings.

[MeGaGiGaGon]

This also applies to byte strings:

>echo 'bf""' | uvx ruff check --output-format concise -
-:1:3: SyntaxError: Simple statements must be separated by newlines or semicolons
Found 1 error.

And all other incompatible string prefixes

[MeGaGiGaGon]

Hm, I wonder when this was added, since I don't get extra info on 3.14

>uvx python@3.14 -c 'uf"a"'
  File "<string>", line 1
    uf"a"
      ^^^
SyntaxError: invalid syntax
>uvx python@3.14 --version
Python 3.14.0a6

[dylwil3]

I think here: python/cpython#133197

uv now ships the latest beta for Python 3.14 so you should be able to update to that one!