fix test markers in test_exceptions.py

Author: ShaharNaveh

Lib/test/test_exceptions.py

@@ -1152,6 +1152,7 @@ class C(Exception):
         self.assertIs(c.__context__, b)
         self.assertIsNone(b.__context__)
 
+    @unittest.skip("TODO: RUSTPYTHON; Infinite loop")
     def test_no_hang_on_context_chain_cycle1(self):
         # See issue 25782. Cycle in context chain.
 
@@ -1207,6 +1208,7 @@ class C(Exception):
         self.assertIs(b.__context__, a)
         self.assertIs(a.__context__, c)
 
+    @unittest.skip("TODO: RUSTPYTHON; Infinite loop")
     def test_no_hang_on_context_chain_cycle3(self):
         # See issue 25782. Longer context chain with cycle.