remove update-dependabot action

.github/workflows/update-dependabot.yml

@@ -1,36 +0,0 @@
-name: Update dependabot.yml
-
-on:
-  workflow_dispatch:
-
-permissions:
-  contents: read
-
-jobs:
-
-  get-supported-branches:
-    uses: spring-io/spring-security-release-tools/.github/workflows/retrieve-spring-supported-versions.yml@actions-v1
-    with:
-      project: spring-security
-      type: oss
-      repository_name: spring-projects/spring-security
-
-  main:
-    runs-on: ubuntu-latest
-    needs: [get-supported-branches]
-    if: ${{ (github.repository == 'spring-projects/spring-security') && (github.ref == 'refs/heads/main') }}
-    permissions:
-      contents: write
-    steps:
-      - uses: actions/checkout@v4
-        with:
-          fetch-depth: 1
-      - uses: spring-io/spring-security-release-tools/.github/actions/generate-dependabot-yml@actions-v1
-        name: Update dependabot.yml
-        with:
-          gradle-branches: ${{ needs.get-supported-branches.outputs.supported_versions }},main
-          github-actions-branches: ${{ needs.get-supported-branches.outputs.supported_versions }},main,docs-build
-          gh-token: ${{ secrets.GITHUB_TOKEN }}
-      - uses: stefanzweifel/git-auto-commit-action@v5
-        with:
-          commit_message: Update dependabot.yml