Address repo-review issue: GH212: Require GHA update grouping

Projects should group their updates to avoid extra PRs and stay in sync.
This is now supported by dependabot since June 2023.

Should have something like this in .pre-commit-config.yaml:

https://learn.scientific-python.org/development/guides/repo-review/?repo=populse%2Fcapsul&branch=3.0

.github/dependabot.yml

@@ -5,3 +5,7 @@ updates:
     directory: "/"
     schedule:
       interval: "weekly"
+    groups:
+      actions:
+        patterns:
+          - "*"