Group auto dependency updates into one PR per ecosystem (#9496)

https://github.com/FreshRSS/FreshRSS/pull/9401#issuecomment-5984319483

(aside from npm exceptions for eslint, stylelint, ... and for separate composer.json: root and lib/)

.github/dependabot.yml

@@ -8,6 +8,10 @@ updates:
       interval: "monthly"
     cooldown:
       default-days: 7
+    groups:
+      github-actions:
+        patterns:
+          - '*'
   - package-ecosystem: "npm"
     directory: "/"
     schedule:
@@ -23,21 +27,41 @@ updates:
       stylelint:
         patterns:
           - "*stylelint*"
+      npm-other:
+        patterns:
+          - '*'
+        exclude-patterns:
+          - "*eslint*"
+          - "globals"
+          - "neostandard"
+          - "*stylelint*"
   - package-ecosystem: "composer"
     directory: "/"
     schedule:
       interval: "monthly"
     cooldown:
       default-days: 7
+    groups:
+      composer-root:
+        patterns:
+          - '*'
   - package-ecosystem: "composer"
     directory: "/lib/"
     schedule:
       interval: "monthly"
     cooldown:
       default-days: 7
+    groups:
+      composer-lib:
+        patterns:
+          - '*'
   - package-ecosystem: "bundler"
     directory: "/docs/"
     schedule:
       interval: "monthly"
     cooldown:
       default-days: 7
+    groups:
+      bundler:
+        patterns:
+          - '*'