Group Dependabot PRs (#316)

[Group Dependabot PRs](https://forum.exercism.org/t/github-dependabot-may-now-produce-combined-prs/18231) as much as possible to reduce re-deployments for automatic updates

Author: mk-mxp

.github/dependabot.yml

@@ -6,8 +6,20 @@ updates:
     directory: "/"
     schedule:
       interval: 'monthly'
+    labels:
+      - 'x:size/tiny'
+    groups:
+      github-actions:
+        patterns:
+          - '*'
   # Keep dependencies for Composer up-to-date
   - package-ecosystem: "composer"
     directory: "/"
     schedule:
       interval: 'monthly'
+    labels:
+      - 'x:size/tiny'
+    groups:
+      composer:
+        patterns:
+          - '*'