CI: add tags to all jobs

Tag all jobs with the DEFAULT_TAG variable so each instance can control
what tags the jobs have.

Signed-off-by: Ross Burton <ross.burton@arm.com>
Signed-off-by: Jon Mason <jon.mason@arm.com>
Signed-off-by: Peter Hoyes <Peter.Hoyes@arm.com>
Signed-off-by: Naveen Saini <naveen.kumar.saini@intel.com>

.gitlab-ci.yml

@@ -2,6 +2,7 @@ image: ghcr.io/siemens/kas/kas:latest-release
 
 variables:
   CPU_REQUEST: ""
+  DEFAULT_TAG: ""
   # These are needed as the k8s executor doesn't respect the container
   # entrypoint by default
   FF_USE_LEGACY_KUBERNETES_EXECUTION_STRATEGY: 0
@@ -13,6 +14,8 @@ stages:
 
 # Common job fragment to get a worker ready
 .setup:
+  tags:
+    - $DEFAULT_TAG
   stage: build
   interruptible: true
   variables:
@@ -65,7 +68,8 @@ machine-coverage:
   script:
     - ./ci/check-machine-coverage
   coverage: '/Coverage: \d+/'
-
+  tags:
+    - $DEFAULT_TAG
 
 #
 # Build stage, the actual build jobs