Fix label-sync failure: quote YAML color values parsed as numbers

Fix label-sync failure: quote YAML color values parsed as numbers

Author: dill-lk

.github/labels.yml

@@ -108,7 +108,7 @@
   description: Docker-related changes
 
 - name: tools
-  color: 5319e7
+  color: "5319e7"
   description: Tools and scripts
 
 - name: dependencies
@@ -137,7 +137,7 @@
   description: Good for newcomers
 
 - name: help-wanted
-  color: 008672
+  color: "008672"
   description: Extra attention is needed
 
 - name: first-time-contributor