Update tryghost/actions digest to 2ad8c9a (#965)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

.github/workflows/publish.yml

@@ -96,7 +96,7 @@ jobs:
         if: steps.pubs.outputs.projects != ''
         run: npx nx release publish --projects=${{ steps.pubs.outputs.projects }} ${{ (github.event.inputs['dry-run'] == 'true' && '--dry-run') || '' }}
 
-      - uses: tryghost/actions/actions/slack-build@a20bdddba43405b5702a60bcc4d16bb0923a4383 # main
+      - uses: tryghost/actions/actions/slack-build@2ad8c9a006b0f0b320bfb8c935706b645ca9409c # main
         if: failure()
         with:
           status: ${{ job.status }}

.github/workflows/test.yml

@@ -58,7 +58,7 @@ jobs:
 
       - uses: codecov/codecov-action@fb8b3582c8e4def4969c97caa2f19720cb33a72f # v7
 
-      - uses: tryghost/actions/actions/slack-build@a20bdddba43405b5702a60bcc4d16bb0923a4383 # main
+      - uses: tryghost/actions/actions/slack-build@2ad8c9a006b0f0b320bfb8c935706b645ca9409c # main
         if: failure() && github.event_name == 'push' && github.ref == 'refs/heads/main'
         with:
           status: ${{ job.status }}