ci(CAT-2275): add Twingate setup step to GitHub Actions workflow

Adds the Twingate installation step in `.github/workflows/...` using `twingate/github-action@v1`.
The action uses the `${{ secrets.TWINGATE_KEY }}` to establish secure access to internal resources.

This enables the workflow to access protected infrastructure during CI runs.

Author: imaqsood

.github/workflows/module_acceptance.yml

@@ -65,7 +65,7 @@ jobs:
   acceptance:
     name: "Acceptance tests (${{matrix.platforms.label}}, ${{matrix.collection}})"
     needs: "setup_matrix"
-    runs-on: ${{ inputs.runs_on }}
+    runs-on: ubuntu-latest
     timeout-minutes: 180
     strategy:
       fail-fast: false
@@ -77,6 +77,10 @@ jobs:
       FACTER_GEM_VERSION: 'https://github.com/puppetlabs/facter#main'  # why is this set?
 
     steps:
+      - name: "Install Twingate"
+        uses: "twingate/github-action@v1"
+        with:
+          service-key: ${{ secrets.TWINGATE_KEY }}
 
       - name: "Checkout"
         uses: "actions/checkout@v4"