enclose variables in ${}

.gitlab-ci.yml

----
 variables:
   version: 0.0.$CI_PIPELINE_IID
+
 stages:
   - test
   - build
   - publish
+
 test_job:
   stage: test
   image: public.ecr.aws/docker/library/golang:1.21
   script:
     - go get -t ./...
     - go test -race -v ./...
+
 build_job:
   stage: build
   image: public.ecr.aws/docker/library/golang:1.21
@@ -24,11 +26,12 @@ build_job:
           - amd64
           - arm64
   script: |
-    go build -o webservice_$GOOS_$GOARCH.bin ./*.go
+    go build -o webservice_${GOOS}_${GOARCH}.bin ./*.go
   artifacts:
     paths:
-      - webservice_$GOOS_$GOARCH.bin
-    expire_in: 30 sec
+      - webservice_${GOOS}_${GOARCH}.bin
+    expire_in: 5 min
+
 publish_job:
   stage: publish
   image: public.ecr.aws/ubuntu/ubuntu:22.04_stable