[3.12] gh-110938: More syntax tests for PEP695 funcs and classes (GH-110986) (#111023)

gh-110938: More syntax tests for PEP695 funcs and classes (GH-110986)
(cherry picked from commit 220bcc9)

Co-authored-by: Nikita Sobolev <[email protected]>

Author: miss-islington

Lib/test/test_syntax.py

@@ -1004,11 +1004,26 @@
    Traceback (most recent call last):
    SyntaxError: expected ':'
 
+   >>> def f[T]()
+   ...     pass
+   Traceback (most recent call last):
+   SyntaxError: expected ':'
+
    >>> class A
    ...     pass
    Traceback (most recent call last):
    SyntaxError: expected ':'
 
+   >>> class A[T]
+   ...     pass
+   Traceback (most recent call last):
+   SyntaxError: expected ':'
+
+   >>> class A[T]()
+   ...     pass
+   Traceback (most recent call last):
+   SyntaxError: expected ':'
+
    >>> class R&D:
    ...     pass
    Traceback (most recent call last):