fix: pin GitHub Actions to immutable SHA hashes to prevent supply chain attacks (#1088)

* chore: publish from staged

* fix: pin GitHub Actions to immutable SHA hashes to prevent supply chain attacks

Co-authored-by: simonkurtz-MSFT <84809797+simonkurtz-MSFT@users.noreply.github.com>

* chore: publish from staged

* Clean plugins

* Clean plugins

* Clean plugins

* Fix gem-team plugin

* Reset README.plugins.md

---------

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>
Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>

.github/workflows/validate-readme.yml

@@ -23,12 +23,12 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout code
-        uses: actions/checkout@v4
+        uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4.3.1
         with:
           fetch-depth: 0
 
       - name: Setup Node.js
-        uses: actions/setup-node@v4
+        uses: actions/setup-node@49933ea5288caeca8642d1e84afbd3f7d6820020 # v4.4.0
         with:
           node-version: "20"
 
@@ -66,7 +66,7 @@ jobs:
 
       - name: Comment on PR if files need updating
         if: steps.check-diff.outputs.status == 'failure' && github.event.pull_request.head.repo.permissions.push == true
-        uses: marocchino/sticky-pull-request-comment@v2
+        uses: marocchino/sticky-pull-request-comment@773744901bac0e8cbb5a0dc842800d45e9b2b405 # v2.9.4
         with:
           header: readme-validation
           message: |