Gradle shadow plugin. Based on Kitlith change of build.gradle. Using …

…now library for Slime Commons dependency resolving. Changed gradle.yml accordingly. It produces slimevr.jar file

.github/workflows/gradle.yml

@@ -51,6 +51,7 @@ jobs:
           java-version: '8'
           distribution: 'adopt'
           cache: 'gradle' # will restore cache of dependencies and wrappers
+
       - name: Grant execute permission for gradlew
         run: chmod +x gradlew