PY-71002 PEP-696: Support new syntax for default types of Type Parameters in new-style declarations

- PEP-696 adds a new syntax for declaring the default types of Type Parameters in new-new style generic classes, functions and type alias statements. Support these grammar changes.
- Store info about default types in stubs for Type Parameters
- Increment the stub version counter in PyFileElementType

GitOrigin-RevId: b6b22e3eaa86ce06132885781e5775a89bf4b840

python/python-psi-api/src/com/jetbrains/python/psi/PyTypeParameter.java

@@ -12,9 +12,16 @@ import org.jetbrains.annotations.Nullable;
  * For more information see <a href="https://peps.python.org/pep-0695/">PEP 695</a>
  */
 public interface PyTypeParameter extends PyAstTypeParameter, PyElement, PsiNameIdentifierOwner, PyTypedElement, StubBasedPsiElement<PyTypeParameterStub> {
+
   @Override
   @Nullable
   default PyExpression getBoundExpression() {
     return (PyExpression)PyAstTypeParameter.super.getBoundExpression();
   }
+
+  @Override
+  @Nullable
+  default PyExpression getDefaultExpression() {
+    return (PyExpression)PyAstTypeParameter.super.getDefaultExpression();
+  }
 }

python/python-psi-api/src/com/jetbrains/python/psi/stubs/PyTypeParameterStub.java

@@ -11,6 +11,9 @@ public interface PyTypeParameterStub extends NamedStub<PyTypeParameter> {
   @Nullable
   String getBoundExpressionText();
 
+  @Nullable
+  String getDefaultExpressionText();
+
   @NotNull
   PyTypeParameter.Kind getKind();
 }