Add stable branches for dependabot

Signed-off-by: Julius Härtl <jus@bitgrid.net>

.github/dependabot.yml

@@ -11,6 +11,58 @@ updates:
   open-pull-requests-limit: 10
   reviewers:
   - juliushaertl
+
+- package-ecosystem: npm
+  target-branch: stable25
+  versioning-strategy: lockfile-only
+  directory: "/"
+  schedule:
+    interval: weekly
+    day: saturday
+    time: "03:00"
+    timezone: Europe/Paris
+  ignore:
+    - dependency-name: "*"
+      update-types: ["version-update:semver-major"]
+  open-pull-requests-limit: 30
+  labels:
+  - 3. to review
+  - dependencies
+
+- package-ecosystem: npm
+  target-branch: stable24
+  versioning-strategy: lockfile-only
+  directory: "/"
+  schedule:
+    interval: weekly
+    day: saturday
+    time: "03:00"
+    timezone: Europe/Paris
+  ignore:
+    - dependency-name: "*"
+      update-types: ["version-update:semver-major"]
+  open-pull-requests-limit: 30
+  labels:
+  - 3. to review
+  - dependencies
+
+- package-ecosystem: npm
+  target-branch: stable23
+  versioning-strategy: lockfile-only
+  directory: "/"
+  schedule:
+    interval: weekly
+    day: saturday
+    time: "03:00"
+    timezone: Europe/Paris
+  ignore:
+    - dependency-name: "*"
+      update-types: ["version-update:semver-major"]
+  open-pull-requests-limit: 30
+  labels:
+  - 3. to review
+  - dependencies
+
 - package-ecosystem: composer
   directory: "/"
   schedule: