Pin dependencies (#2355)

Co-authored-by: elastic-renovate-prod[bot] <174716857+elastic-renovate-prod[bot]@users.noreply.github.com>
Co-authored-by: Michael Wolf <michael.wolf@elastic.co>

.github/workflows/docs-preview-comment.yml

@@ -10,7 +10,7 @@ jobs:
   doc-preview:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/github-script@v6
+      - uses: actions/github-script@d7906e4ad0b1822421a7e6a35d5ca353c962f410 # v6
         name: Add doc preview links
         with:
           script: |

.github/workflows/stale.yml

@@ -15,7 +15,7 @@ jobs:
 
     steps:
     - name: "Check PRs"
-      uses: actions/stale@v4
+      uses: actions/stale@a20b814fb01b71def3bd6f56e7494d667ddf28da # v4
       with:
         repo-token: ${{ secrets.GITHUB_TOKEN }}
         stale-pr-message: 'This PR is stale because it has been open for 60 days with no activity.'

.github/workflows/test.yml

@@ -7,8 +7,8 @@ jobs:
     runs-on: ubuntu-20.04
     name: Unit Tests
     steps:
-      - uses: actions/checkout@v2
-      - uses: actions/setup-python@v2
+      - uses: actions/checkout@ee0669bd1cc54295c223e0bb666b733df41de1c5 # v2
+      - uses: actions/setup-python@e9aba2c848f5ebd159c070c61ea2c4e2b122355e # v2
         with:
           python-version: '3.x'
       - run: git fetch --prune --unshallow --tags