Migrate release process to GitHub Actions

Complete migration to GitHub Actions.

See gh-411

Author: philwebb

Diff for: .github/artifacts.spec

@@ -0,0 +1,17 @@
+{
+  "files": [
+    {
+      "aql": {
+        "items.find": {
+          "$and": [
+            {
+              "@build.name": "${buildName}",
+              "@build.number": "${buildNumber}"
+            }
+          ]
+        }
+      },
+      "target": "nexus/"
+    }
+  ]
+}

Diff for: .github/workflows/promote.yml

@@ -33,5 +33,25 @@ jobs:
     name: Promote
     runs-on: ubuntu-latest
     steps:
-    - name: Promote
-      run: echo "Promote happens here"
+    - name: Check Out
+      uses: actions/checkout@v4
+    - name: Set Up JFrog CLI
+      uses: jfrog/setup-jfrog-cli@7c95feb32008765e1b4e626b078dfd897c4340ad # v4.1.2
+      env:
+        JF_ENV_SPRING: ${{ secrets.JF_ARTIFACTORY_SPRING }}
+    - name: Download Release Artifacts
+      shell: bash
+      run: jf rt download --spec ./.github/artifacts.spec --spec-vars 'buildName=${{ format('spring-javaformat-{0}', inputs.version) }};buildNumber=${{ inputs.build-number }}'
+    - name: Check Maven Central Sync Status
+      id: check-sync-status
+      run: |
+        url=${{ format('https://repo.maven.apache.org/maven2/io/spring/javaformat/spring-javaformat/{0}/spring-javaformat-{0}.pom', inputs.version) }}
+        status_code=$( curl --write-out '%{http_code}' --head --silent --output /dev/null ${url} )
+        if [ "${status_code}" != 200 ] && [ "${status_code}" != 404 ]; then
+          echo "Unexpected status code ${status_code}"
+          exit 1
+        fi
+        echo "status-code=${status_code}" >> $GITHUB_OUTPUT
+    - name: Sync to Maven Central
+      run: echo "Sync Here"
+      if: ${{ steps.check-sync-status.outputs.status-code == '404' }}