Remove decrypted vault temp_file mistakenly left from patch making vault edit idempotent

This bug was introduced in commit f8bf2ba on July 27.  Hasn't gone out
in a release yet.

lib/ansible/parsing/vault/__init__.py

@@ -257,6 +257,7 @@ class VaultEditor:
 
         # Do nothing if the content has not changed
         if existing_data == tmpdata and not force_save:
+            os.remove(tmp_path)
             return
 
         # create new vault