Improve GH Action PR assign + labeling (#3584)

Signed-off-by: Carlisia <carlisia@vmware.com>

.github/workflows/auto_assign_prs.yml

@@ -3,7 +3,7 @@ name: "Auto Assign PR Reviewers"
 # This should mean PRs from forks are supported.
 on:
   pull_request_target:
-    types: [opened, reopened, synchronize, ready_for_review]
+    types: [opened, reopened, ready_for_review]
 
 jobs:
   # Automatically assigns reviewers and owner
@@ -13,12 +13,4 @@ jobs:
       - uses: kentaro-m/auto-assign-action@v1.1.1
         with:
           configuration-path: ".github/auto_assign.yml"
-          repo-token: "${{ secrets.GITHUB_TOKEN }}"
-  # Automatically labels PRs based on file globs in the change.
-  triage:
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/labeler@v3
-        with:
-          repo-token: "${{ secrets.GITHUB_TOKEN }}"
-          configuration-path: .github/labels.yml
+          repo-token: "${{ secrets.GITHUB_TOKEN }}"

.github/workflows/auto_label_prs.yml

@@ -0,0 +1,19 @@
+name: "Auto Label PRs"
+# pull_request_target means that this will run on pull requests, but in the context of the base repo.
+# This should mean PRs from forks are supported. 
+# Because it includes the `synchronize` parameter, any push of a new commit to the HEAD ref of a pull request
+# will trigger this process.
+
+on:
+  pull_request_target:
+    types: [opened, reopened, synchronize, ready_for_review]
+
+jobs:
+  # Automatically labels PRs based on file globs in the change.
+  triage:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/labeler@v3
+        with:
+          repo-token: "${{ secrets.GITHUB_TOKEN }}"
+          configuration-path: .github/labels.yml