Reduce gh actions time by ~75% (~6 minutes)

.github/workflows/build.yml

@@ -4,52 +4,14 @@ on: ["pull_request", "push"]
 
 jobs:
   build:
-    strategy:
+    runs-on: "ubuntu-20.04"
-      matrix:
-        os: ["ubuntu-latest"]
-    runs-on: "${{ matrix.os }}"
     steps:
-    - name: "Checkout Repository"
+      - name: "Checkout Repository"
-      uses: "actions/checkout@v2.3.4"
+        uses: "actions/checkout@v2.3.4"
-    - name: "Setup JDK 16"
+      - name: "Setup JDK 16"
-      uses: "actions/setup-java@v2.1.0"
+        uses: "actions/setup-java@v2.1.0"
-      with:
+        with:
           distribution: "adopt"
           java-version: "16"
-    - name: "Cache Gradle"
+      - name: "Clean Build"
-      uses: "actions/cache@v2.1.6"
+        run: "./gradlew clean build -x test"
-      with:
-        path: |
-          "~/.gradle/caches"
-          "~/.gradle/wrapper"
-        key: "${{ runner.os }}-gradle-${{ hashFiles('**/*.gradle*', '**/gradle-wrapper.properties') }}"
-        restore-keys: |
-          "${{ runner.os }}-gradle-"
-    - name: "Cache Local Maven Repository"
-      uses: "actions/cache@v2.1.6"
-      with:
-        path: "~/.m2/repository"
-        key: "${{ runner.os }}-11-maven-${{ hashFiles('**/pom.xml') }}"
-        restore-keys: |
-          "${{ runner.os }}-11-maven-"
-    - name: "Cache BuildTools Decompiled Code"
-      uses: "actions/cache@v2.1.6"
-      with:
-        path: "$GITHUB_WORKSPACE/work"
-        key: "${{ runner.os }}-buildtools"
-        restore-keys: |
-          "${{ runner.os }}-buildtools"
-    - name: "Test Environment"
-      run: "echo $GITHUB_WORKSPACE"
-    - name: "Download BuildTools"
-      run: "wget https://hub.spigotmc.org/jenkins/job/BuildTools/lastSuccessfulBuild/artifact/target/BuildTools.jar"
-    - name: "Run BuildTools"
-      run: "java -jar BuildTools.jar --rev 1.17.1"
-    - name: "Clean Build"
-      run: "./gradlew clean build sourcesJar javadocJar -x test"
-    - name: Cleanup Gradle Cache
-      # Remove some files from the Gradle cache, so they aren't cached by GitHub Actions.
-      # Restoring these files from a GitHub Actions cache might cause problems for future builds.
-      run: |
-        rm -f ~/.gradle/caches/modules-2/modules-2.lock
-        rm -f ~/.gradle/caches/modules-2/gc.properties