Automatically apply the project proposal and IP labels to PRs (#3982)

.github/auto-label.json

@@ -1,5 +1,7 @@
 {
   "rules": {
-    "migrations": ["**/migrations/**/*"]
+    "migrations": ["**/migrations/**/*"],
+    "🧭 project: proposal": ["**/*project_proposal*"],
+    "🧭 project: implementation plan": ["**/*implementation_plan*"]
   }
 }