Add GitHub Actions workflow for plugin release

This workflow triggers on pushes with version tags. It builds the plugin, signs the JAR, creates a draft release, and uploads the signed JAR as a release asset.

.github/workflows/release_plugin.yml

@@ -0,0 +1,54 @@
+name: Release Plugin
+
+on:
+  push:
+    tags:
+      - 'v*'
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v3
+
+      - name: Set up JDK 17
+        uses: actions/setup-java@v3
+        with:
+          distribution: 'temurin'
+          java-version: '17'
+
+      - name: Build the Plugin
+        run: ./gradlew buildPlugin
+
+      - name: Sign the Plugin JAR
+        run: ./gradlew signPlugin
+        env:
+          CERTIFICATE_CHAIN: ${{ secrets.CERTIFICATE_CHAIN }}
+          PRIVATE_KEY: ${{ secrets.PRIVATE_KEY }}
+          PRIVATE_KEY_PASSWORD: ${{ secrets.PRIVATE_KEY_PASSWORD }}
+
+      - name: Create Release
+        id: create_release
+        uses: actions/create-release@v1
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        with:
+          tag_name: ${{ github.ref }}
+          release_name: Release ${{ github.ref }}
+          body: |
+            Changes in this release:
+            - TBD
+          draft: true
+          prerelease: false
+
+      - name: Upload Signed JAR to Release
+        uses: actions/upload-release-asset@v1
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        with:
+          upload_url: ${{ steps.create_release.outputs.upload_url }}
+          asset_path: build/distributions/*.zip
+          asset_name: plugin-signed.jar
+          asset_content_type: application/java-archive