[PR #5954/3ec2fde2 backport][stable-6] Add attributes to package manager modules (#6062)

Add attributes to package manager modules (#5954)

Add attributes to package manager modules.

(cherry picked from commit 3ec2fde2c6)

Co-authored-by: Felix Fontein <felix@fontein.de>

plugins/modules/apt_repo.py

@@ -19,6 +19,13 @@ description:
 notes:
     - This module works on ALT based distros.
     - Does NOT support checkmode, due to a limitation in apt-repo tool.
+extends_documentation_fragment:
+  - community.general.attributes
+attributes:
+  check_mode:
+    support: none
+  diff_mode:
+    support: none
 options:
   repo:
     description: