Update tests.yaml

Author: Hillkorn

.github/workflows/tests.yaml

@@ -25,6 +25,6 @@ jobs:
         uses: gradle/wrapper-validation-action@e6e38bacfdf1a337459f332974bb2327a31aaf4b
 
       - name: Build with Gradle
-        uses: gradle/gradle-build-action@2.4.2
+        uses: gradle/gradle-build-action@v2.4.2
         with:
           arguments: check