CI: Update some comments

.github/dependabot.yml

@@ -9,5 +9,7 @@ updates:
     schedule:
       interval: "daily"
     ignore:
-      # ReadTheDocs is staying on v1.
+      # We need to decide on when we upgrade Sphinx manually,
+      # as historically, this has been proven to often imply larger changes
+      # (RTD compat, upgrading extensions, other dependencies, our content, etc.).
       - dependency-name: "sphinx"

.github/workflows/sync_class_ref.yml

@@ -3,9 +3,10 @@ name: Sync Class Reference
 on:
   workflow_dispatch:
   # Scheduled updates only run on the default/master branch.
+  # Other branches need to be run manually (usually after a new release for that branch).
   schedule:
-    # Run it at night (European time) every Saturday.
-    # The offset is there to try and avoid the high load times.
+    # Run it at (European) night time every Saturday.
+    # The offset is there to try and avoid high load times.
     - cron: '15 3 * * 6'
 
 # Make sure jobs cannot overlap.