chore: pin GitHub Actions to SHA hashes for security

- Pin actions/checkout, setup-python, cache
- Dependabot will handle version updates via PRs

Ticket: 6361

Author: Emmanuel Ukoha

.github/workflows/publish-docs.yml

@@ -9,8 +9,8 @@ jobs:
   deploy:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
-      - uses: actions/setup-python@v4
+      - uses: actions/checkout@f43a0e5ff2bd294095638e18286ca9a3d1956744  # v3.6.0
+      - uses: actions/setup-python@7f4fc3e22c37d6ff65e88745f38bd3157c663f7c  # v4.9.1
         with:
           python-version: 3.x
       - uses: actions/cache@v3