Upgrade instances capacty infra

Move 'testing-preview' and 'pre-release-preview' to higher memory instances 'e2-standard-2'.

Author: jpraynaud

.github/workflows/ci.yml

@@ -445,7 +445,7 @@ jobs:
           terraform_backend_bucket: hydra-terraform-admin
           google_region: europe-west1
           google_zone: europe-west1-b
-          google_machine_type: e2-medium
+          google_machine_type: e2-standard-2
 
     runs-on: ubuntu-22.04
 

.github/workflows/pre-release.yml

@@ -211,7 +211,7 @@ jobs:
           terraform_backend_bucket: hydra-terraform-admin
           google_region: europe-west1
           google_zone: europe-west1-b
-          google_machine_type: e2-medium
+          google_machine_type: e2-standard-2
 
     runs-on: ubuntu-22.04