Update GHA service account for docker build workflows (#2264)

Switch workload identity service account from
github-gcloud-deployer@roboflow-artifacts to
gha-inference@roboflow-staging for CPU and GPU docker build workflows.

Co-authored-by: Paweł Pęczek <146137186+PawelPeczek-Roboflow@users.noreply.github.com>

Author: ecarrara

.github/workflows/docker.cpu.yml

@@ -66,7 +66,7 @@ jobs:
         id: auth
         with:
           workload_identity_provider: 'projects/391662651862/locations/global/workloadIdentityPools/github-actions/providers/github'
-          service_account: 'gha-inference@roboflow-artifacts.iam.gserviceaccount.com'
+          service_account: 'gha-inference@roboflow-staging.iam.gserviceaccount.com'
           token_format: 'access_token'
       - name: Login to Google Artifact Registry
         uses: docker/login-action@v3

.github/workflows/docker.gpu.yml

@@ -64,7 +64,7 @@ jobs:
         id: auth
         with:
           workload_identity_provider: 'projects/391662651862/locations/global/workloadIdentityPools/github-actions/providers/github'
-          service_account: 'gha-inference@roboflow-artifacts.iam.gserviceaccount.com'
+          service_account: 'gha-inference@roboflow-staging.iam.gserviceaccount.com'
           token_format: 'access_token'
       - name: Login to Google Artifact Registry
         uses: docker/login-action@v3