chore: Remove stable23 from dependabot

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

.github/dependabot.yml

@@ -46,23 +46,6 @@ updates:
   - 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: