Don't remove data dirs from vendor directory (#8173)

Makefile

@@ -477,7 +477,7 @@ clean: stop-docker ## Clean up everything except persistant server data.
 
 	cd $(BUILD_WEBAPP_DIR) && $(MAKE) clean
 
-	find . -type d -name data | xargs rm -r
+	find . -type d -name data -not -path './vendor/*' | xargs rm -r
 	rm -rf logs
 
 	rm -f mattermost.log