PY-35190 Fix resolving the register method of ABCMeta

The root cause was introduced in PY-23540 (see cb598c94c5).
Namely, abs.ABCMeta was explicitly filtered out from the list of metaclasses in
`PyClassImpl.getMostDerivedClassType` because for some reason in Typeshed stubs for
Python 2 `basestring`, and hence `str`, uses `ABCMeta` as its metaclass,
which is not true at runtime. It caused a metaclass conflict when inheriting `str`
with another user-defined metaclass (`ABCMeta` and a user metaclass didn't extend
each other), so we didn't detect any metaclass in a class as a result.

I've updated Typeshed stubs for Python 2 manually to process ABCMeta normally.
We don't update these stubs anyway, so these changes won't be lost on a future
Typeshed sync.

GitOrigin-RevId: 680e9fa890d00ea63987f3cf73e636e430685f34

python/helpers/typeshed/stdlib/@python2/__builtin__.pyi

@@ -269,7 +269,7 @@ class complex:
     def __hash__(self) -> int: ...
     def __nonzero__(self) -> bool: ...
 
-class basestring(metaclass=ABCMeta): ...
+class basestring: ...
 
 class unicode(basestring, Sequence[unicode]):
     @overload

python/helpers/typeshed/stdlib/@python2/builtins.pyi

@@ -269,7 +269,7 @@ class complex:
     def __hash__(self) -> int: ...
     def __nonzero__(self) -> bool: ...
 
-class basestring(metaclass=ABCMeta): ...
+class basestring: ...
 
 class unicode(basestring, Sequence[unicode]):
     @overload

python/python-psi-impl/src/com/jetbrains/python/psi/impl/PyClassImpl.java

@@ -1515,7 +1515,6 @@ public class PyClassImpl extends PyBaseElementImpl<PyClassStub> implements PyCla
     try {
       return classTypes
         .stream()
-        .filter(t -> !PyNames.ABC_META.equals(t.getClassQName()))
         .max(
           (t1, t2) -> {
             if (Objects.equals(t1, t2)) {

python/testSrc/com/jetbrains/python/inspections/Py3UnresolvedReferencesInspectionTest.java

@@ -319,4 +319,16 @@ public class Py3UnresolvedReferencesInspectionTest extends PyInspectionTestCase
   public void testNoWarningForTypeGetItem() {
     doTestByText("expr: type[str]");
   }
+
+  // PY-35190
+  public void testABCMetaRegisterMethod() {
+    doTestByText("""
+                 from abc import ABCMeta
+                 
+                 class MyABC(metaclass=ABCMeta):
+                     pass
+                 
+                 MyABC.register(str)
+                 """);
+  }
 }