fix(ci): update runner label from local-ubuntu-latest-cartsnitch to runners-cartsnitch

ARC runner scale set was reconfigured with label `runners-cartsnitch`.
All CI jobs were queued indefinitely because no runner matched the old label.

Relates to infra#20

Co-Authored-By: Paperclip <noreply@paperclip.ing>

.github/workflows/ci.yml

@@ -20,7 +20,7 @@ env:
 
 jobs:
   lint:
-    runs-on: local-ubuntu-latest-cartsnitch
+    runs-on: runners-cartsnitch
     steps:
       - uses: actions/checkout@v4
       - uses: actions/setup-node@v4
@@ -34,7 +34,7 @@ jobs:
         run: npx tsc --noEmit
 
   test:
-    runs-on: local-ubuntu-latest-cartsnitch
+    runs-on: runners-cartsnitch
     steps:
       - uses: actions/checkout@v4
       - uses: actions/setup-node@v4
@@ -46,7 +46,7 @@ jobs:
         run: npx vitest run
 
   build-and-push:
-    runs-on: local-ubuntu-latest-cartsnitch
+    runs-on: runners-cartsnitch
     needs: [lint, test]
     steps:
       - uses: actions/checkout@v4
@@ -68,12 +68,6 @@ jobs:
             type=sha,prefix=sha-
             type=raw,value=latest,enable=${{ github.ref == 'refs/heads/main' }}
 
-      - name: Log in to Docker Hub
-        uses: docker/login-action@v3
-        with:
-          username: ${{ secrets.DOCKERHUB_USERNAME }}
-          password: ${{ secrets.DOCKERHUB_TOKEN }}
-
       - name: Build and push Docker image
         uses: docker/build-push-action@v6
         with: