feat(buildx): add automatic Buildx cleanup for stale builders and end-of-run cache pruning

ts/tsdocker.config.ts

@@ -11,6 +11,11 @@ const buildConfig = async (): Promise<ITsDockerConfig> => {
     platforms: ['linux/amd64'],
     push: false,
     testDir: undefined,
+    autoCleanup: true,
+    cleanupOnStart: true,
+    buildxPruneUntil: '168h',
+    buildxPruneMaxUsedSpace: '2gb',
+    removeCiBuilders: true,
   });
   return config;
 };