Do not generate dependency graph in cache-cleanup

- Allow environment variables to be overridden by system properties in dependency-graph initscript
- Set `GITHUB_DEPENDENCY_GRAPH_ENABLED=false` when executing Gradle for cache cleanup

src/cache-cleaner.ts

@@ -42,7 +42,8 @@ export class CacheCleaner {
         )
         fs.writeFileSync(path.resolve(cleanupProjectDir, 'build.gradle'), 'task("noop") {}')
 
-        await exec.exec(`gradle -g ${this.gradleUserHome} --no-daemon --build-cache --no-scan --quiet noop`, [], {
+        const gradleCommand = `gradle -g ${this.gradleUserHome} --no-daemon --build-cache --no-scan --quiet -DGITHUB_DEPENDENCY_GRAPH_ENABLED=false noop`
+        await exec.exec(gradleCommand, [], {
             cwd: cleanupProjectDir
         })
     }