Fix typos mostly in comments, docs and test names (GH-15209)

diff --git a/Lib/test/test_gc.py b/Lib/test/test_gc.py
index 2dab530..311143d 100644
--- a/Lib/test/test_gc.py
+++ b/Lib/test/test_gc.py
@@ -912,7 +912,7 @@
     def test_collect_garbage(self):
         self.preclean()
         # Each of these cause four objects to be garbage: Two
-        # Uncolectables and their instance dicts.
+        # Uncollectables and their instance dicts.
         Uncollectable()
         Uncollectable()
         C1055820(666)