bpo-38875: test_capi: trashcan tests require cpu resource (GH-17314)

test_capi: trashcan tests now require the test "cpu" resource.
diff --git a/Lib/test/test_capi.py b/Lib/test/test_capi.py
index 2024435..e65973c 100644
--- a/Lib/test/test_capi.py
+++ b/Lib/test/test_capi.py
@@ -351,9 +351,11 @@
         for i in range(1000):
             L = MyList((L,))
 
+    @support.requires_resource('cpu')
     def test_trashcan_python_class1(self):
         self.do_test_trashcan_python_class(list)
 
+    @support.requires_resource('cpu')
     def test_trashcan_python_class2(self):
         from _testcapi import MyList
         self.do_test_trashcan_python_class(MyList)