Split the release workflow out from the build action

.github/workflows/build.yml

@@ -1,5 +1,5 @@
 name: build
-on: [ push, pull_request, release ]
+on: [ push, pull_request ]
 
 env:
   ORG_GRADLE_PROJECT_checksumFailOn: build_finish
@@ -63,12 +63,3 @@ jobs:
           NEXUS_USERNAME: ${{ secrets.NEXUS_USERNAME }}
           NEXUS_PASSWORD: ${{ secrets.NEXUS_PASSWORD }}
         run: ./gradlew publishToSonatype
-      - name: Releasing
-        if: >
-          matrix.java == env.MIN_JVM
-          && github.event_name == 'release'
-          && github.event.action == 'created'
-        env:
-          NEXUS_USERNAME: ${{ secrets.NEXUS_USERNAME }}
-          NEXUS_PASSWORD: ${{ secrets.NEXUS_PASSWORD }}
-        run: ./gradlew publishToSonatype closeAndReleaseSonatypeStagingRepository -Prelease

.github/workflows/release.yml

@@ -0,0 +1,31 @@
+name: release
+on:
+  release:
+    types: [created]
+
+jobs:
+  release:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - name: Set up JDK 8
+        uses: actions/setup-java@v1
+        with:
+          java-version: 8
+      - name: Cache Gradle packages
+        uses: actions/cache@v2.1.4
+        with:
+          path: |
+            ~/.gradle/wrapper
+            ~/.gradle/caches
+            ~/.sonar/cache
+          key: ${{ runner.os }}-${{ github.job }}-${{ matrix.java }}-${{ hashFiles('**/*.gradle') }}
+          restore-keys: ${{ runner.os }}-gradle
+      - name: Releasing
+        env:
+          NEXUS_USERNAME: ${{ secrets.NEXUS_USERNAME }}
+          NEXUS_PASSWORD: ${{ secrets.NEXUS_PASSWORD }}
+          ORG_GRADLE_PROJECT_signingKeyId: 20BCF6B1
+          ORG_GRADLE_PROJECT_signingKey: ${{ secrets.OSSRH_GPG_SECRET_KEY }}
+          ORG_GRADLE_PROJECT_signingPassword: ${{ secrets.OSSRH_GPG_SECRET_KEY_PASSWORD }}
+        run: ./gradlew publishToSonatype closeAndReleaseSonatypeStagingRepository -Prelease