ci: fix linter errors - remove concurrency root, remove unused service_name secret

.woodpecker.yml

@@ -2,9 +2,6 @@ when:
   branch: [main, high-performance]
   event: push
 
-concurrency:
-  limit: 4
-
 matrix:
   SERVICE:
     - gateway
@@ -38,8 +35,6 @@ steps:
         from_secret: REGISTRY_USERNAME
       REGISTRY_PASSWORD:
         from_secret: REGISTRY_PASSWORD
-      SERVICE_NAME:
-        from_secret: SERVICE_NAME
     commands:
       - echo "${REGISTRY_PASSWORD}" | docker login "${REGISTRY_HOSTPORT}" -u "${REGISTRY_USERNAME}" --password-stdin
       - docker build -t "${REGISTRY_HOSTPORT}/nxtgauge-rust-${SERVICE}" --build-arg SERVICE_NAME=${SERVICE} -f Dockerfile.simple .