chore(ci): Set up Depot CLI for E2E if required (#4229)

.github/workflows/.reusable-docker-e2e-tests.yml

@@ -22,6 +22,12 @@ on:
         description: The concurrent number of browsers to be used on testing
         required: false
         default: 3
+      use-depot:
+        type: boolean
+        required: false
+        default: >
+          ${{ startsWith(inputs.api-image, 'registry.depot.dev') || 
+            startsWith(inputs.e2e-image, 'registry.depot.dev') }}
 
 jobs:
   run-e2e:
@@ -45,8 +51,12 @@ jobs:
           username: ${{ github.actor }}
           password: ${{ secrets.GITHUB_TOKEN }}
 
+      - name: Set up Depot CLI
+        if: inputs.use-depot
+        uses: depot/setup-action@v1
+
       - name: Login to Depot Registry
-        if: startsWith(inputs.api-image, 'registry.depot.dev') || startsWith(inputs.e2e-image, 'registry.depot.dev')
+        if: inputs.use-depot
         run: depot pull-token | docker login -u x-token --password-stdin registry.depot.dev
 
       - name: Run tests on dockerised frontend