Remove release milestone workflow as it is no longer relevant

Closes gh-46572

.github/workflows/release-milestone.yml

@@ -1,95 +0,0 @@
-name: Release Milestone
-on:
-  push:
-    tags:
-      - v3.4.0-M[0-9]
-      - v3.4.0-RC[0-9]
-permissions:
-  contents: read
-concurrency:
-  group: ${{ github.workflow }}-${{ github.ref }}
-jobs:
-  build-and-stage-release:
-    name: Build and Stage Release
-    if: ${{ github.repository == 'spring-projects/spring-boot' }}
-    runs-on: ${{ vars.UBUNTU_MEDIUM || 'ubuntu-latest' }}
-    steps:
-      - name: Check Out Code
-        uses: actions/checkout@v4
-      - name: Build and Publish
-        id: build-and-publish
-        uses: ./.github/actions/build
-        with:
-          develocity-access-key: ${{ secrets.GRADLE_ENTERPRISE_SECRET_ACCESS_KEY }}
-          gradle-cache-read-only: false
-          publish: true
-      - name: Stage Release
-        uses: spring-io/artifactory-deploy-action@dc1913008c0599f0c4b1fdafb6ff3c502b3565ea # v0.0.2
-        with:
-          build-name: ${{ format('spring-boot-{0}', steps.build-and-publish.outputs.version)}}
-          folder: 'deployment-repository'
-          password: ${{ secrets.ARTIFACTORY_PASSWORD }}
-          repository: 'libs-staging-local'
-          signing-key: ${{ secrets.GPG_PRIVATE_KEY }}
-          signing-passphrase: ${{ secrets.GPG_PASSPHRASE }}
-          uri: 'https://repo.spring.io'
-          username: ${{ secrets.ARTIFACTORY_USERNAME }}
-    outputs:
-      version: ${{ steps.build-and-publish.outputs.version }}
-  verify:
-    name: Verify
-    needs: build-and-stage-release
-    uses: ./.github/workflows/verify.yml
-    secrets:
-      commercial-repository-password: ${{ secrets.COMMERCIAL_ARTIFACTORY_RO_PASSWORD }}
-      commercial-repository-username: ${{ secrets.COMMERCIAL_ARTIFACTORY_RO_USERNAME }}
-      google-chat-webhook-url: ${{ secrets.GOOGLE_CHAT_WEBHOOK_URL }}
-      opensource-repository-password: ${{ secrets.ARTIFACTORY_PASSWORD }}
-      opensource-repository-username: ${{ secrets.ARTIFACTORY_USERNAME }}
-      token: ${{ secrets.GH_ACTIONS_REPO_TOKEN }}
-    with:
-      staging: true
-      version: ${{ needs.build-and-stage-release.outputs.version }}
-  promote-release:
-    name: Promote Release
-    needs:
-      - build-and-stage-release
-      - verify
-    runs-on: ${{ vars.UBUNTU_SMALL || 'ubuntu-latest' }}
-    steps:
-      - name: Set up JFrog CLI
-        uses: jfrog/setup-jfrog-cli@ff5cb544114ffc152db9cea1cd3d5978d5074946 # v4.5.11
-        env:
-          JF_ENV_SPRING: ${{ secrets.JF_ARTIFACTORY_SPRING }}
-      - name: Promote build
-        run: jfrog rt build-promote ${{ format('spring-boot-{0}', needs.build-and-stage-release.outputs.version)}} ${{ github.run_number }} libs-milestone-local
-  trigger-docs-build:
-    name: Trigger Docs Build
-    needs:
-      - build-and-stage-release
-      - verify
-    permissions:
-      actions: write
-    runs-on: ubuntu-latest
-    steps:
-      - name: Run Deploy Docs Workflow
-        env:
-          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-        run: gh workflow run deploy-docs.yml --repo ${{ github.repository }} -r docs-build -f build-refname=${{ github.ref_name }} -f build-version=${{ needs.build-and-stage-release.outputs.version }}
-  create-github-release:
-    name: Create GitHub Release
-    needs:
-      - build-and-stage-release
-      - promote-release
-      - trigger-docs-build
-    runs-on: ${{ vars.UBUNTU_SMALL || 'ubuntu-latest' }}
-    steps:
-      - name: Check Out Code
-        uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
-      - name: Create GitHub Release
-        uses: ./.github/actions/create-github-release
-        with:
-          commercial: ${{ vars.COMMERCIAL }}
-          milestone: ${{ needs.build-and-stage-release.outputs.version }}
-          pre-release: true
-          token: ${{ secrets.GH_ACTIONS_REPO_TOKEN }}