ast.parse allows positional-only params with old feature_version

[hauntsaninja]

The following should raise SyntaxError:

ast.parse('def foo(x, /): ...', feature_version=(3, 7))

[lysnikolaou]

Oops, after merging #94997, I figured out that we should probably do this for lambda parameters as well, right?

❯ ./python                  
Python 3.12.0a0 (heads/main:b5e3ea2862, Aug 12 2022, 19:50:42) [GCC 11.2.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import ast
>>> ast.parse('lambda x, /: ...')
<ast.Module object at 0x7fb4a02b8140>
>>> ast.parse('lambda x, /: ...', feature_version=(3, 7))
<ast.Module object at 0x7fb4a02b76b0>

[hauntsaninja]

Great point, opened #95934