[3.10] bpo-25130: Add calls of gc.collect() in tests to support PyPy (GH-28005) (GH-28027)

(cherry picked from commit 2a8127cafe1d196f858a3ecabf5f1df3eebf9a12)

Co-authored-by: Serhiy Storchaka <storchaka@gmail.com>
diff --git a/Lib/test/test_tempfile.py b/Lib/test/test_tempfile.py
index 3a3f6a9..f1d4837 100644
--- a/Lib/test/test_tempfile.py
+++ b/Lib/test/test_tempfile.py
@@ -430,6 +430,7 @@ def test_choose_directory(self):
             self.do_create(dir=dir).write(b"blat")
             self.do_create(dir=pathlib.Path(dir)).write(b"blat")
         finally:
+            support.gc_collect()  # For PyPy or other GCs.
             os.rmdir(dir)
 
     def test_file_mode(self):
@@ -880,6 +881,8 @@ def test_many(self):
         extant = list(range(TEST_FILES))
         for i in extant:
             extant[i] = self.do_create(pre="aa")
+        del extant
+        support.gc_collect()  # For PyPy or other GCs.
 
 ##     def test_warning(self):
 ##         # mktemp issues a warning when used