Update .gitlab-ci.yml

.gitlab-ci.yml

+variables:
+  NO_CACHE: 'true'
+  
 stages:
   - build
-  - build_tag
-  - build_stable
 
 build_latest:
   stage: build
@@ -12,7 +13,7 @@ build_latest:
   script: 'echo "Building Docker image..."' # unused but this line is required by GitLab CI
 
 build_tag:
-  stage: build_tag
+  stage: build
   only:
     - tags
   tags:
@@ -25,7 +26,7 @@ build_tag:
     
 
 build_stable:
-  stage: build_stable
+  stage: build
   when: manual
   only:
     - tags