ci: Fix problem locating build component

The transitive build script dependency `org.jfrog.buildinfo:build-info-extractor:2.3.2` cannot be found.

This commit adds Groovy's artifactory repo to the build script repositories, to make the build find the missing dependency.

Author: matrei

build.gradle

@@ -28,7 +28,7 @@ buildscript {
         maven { url 'https://plugins.gradle.org/m2/' }
         // uncomment next repo if jcenter isn't available
         // we have some build components mirrored there
-//        maven { url 'https://groovy.jfrog.io/artifactory/libs-release-local/' }
+        maven { url 'https://groovy.jfrog.io/artifactory/libs-release-local/' }
         maven { url 'https://oss.sonatype.org/content/repositories/snapshots' }
         maven { url 'https://jitpack.io' }
     }