[7.x] Fix typo (collections.abs -> collections.abc) to restore Python 3.9 support

Co-authored-by: Jeppe Fihl-Pearson <tenzer@tenzer.dk>

elasticsearch/compat.py

@@ -33,7 +33,7 @@ else:
     from queue import Queue
 
 try:
-    from collections.abs import Mapping
+    from collections.abc import Mapping
 except ImportError:
     from collections import Mapping