fix: replace embedded python with sed in deploy-gke manifest update step

.gitea/workflows/deploy-gke.yaml

@@ -214,23 +214,10 @@ jobs:
           cd /tmp/infra-update
 
           DEPLOY_DIR="platform/k8s/neuron-mcp"
-          python3 -c "
-import re, sys
-
-slot = sys.argv[1]
-idle = sys.argv[2]
-
-def set_replicas(path, count):
-    with open(path) as f:
-        content = f.read()
-    content = re.sub(r'^(  replicas: )\d+', r'\g<1>' + str(count), content, count=1, flags=re.MULTILINE)
-    with open(path, 'w') as f:
-        f.write(content)
-    print(f'  {path}: replicas set to {count}')
-
-set_replicas(f'{DEPLOY_DIR}/deployment-{slot}.yaml', 1)
-set_replicas(f'{DEPLOY_DIR}/deployment-{idle}.yaml', 0)
-" "$SLOT" "$IDLE"
+          sed -i "s/^  replicas: .*/  replicas: 1/" "${DEPLOY_DIR}/deployment-${SLOT}.yaml"
+          sed -i "s/^  replicas: .*/  replicas: 0/" "${DEPLOY_DIR}/deployment-${IDLE}.yaml"
+          echo "  deployment-${SLOT}.yaml: replicas set to 1"
+          echo "  deployment-${IDLE}.yaml: replicas set to 0"
 
           git config user.email "ci@neurontechnologies.ai"
           git config user.name "Neuron CI"