CI: move CPU_REQUEST from .build to .setup

We were only setting the k8s CPU request in .build jobs not .setup. This
was intentional initially so that only the build jobs get more resources,
but some of the non-.build jobs are resource-heavy. For example, the
pending-updates job has to parse the entire metadata from scratch, and
that sometimes takes longer than usual when we only have two cores to
use.

Signed-off-by: Ross Burton <ross.burton@arm.com>
Signed-off-by: Jon Mason <jon.mason@arm.com>

.gitlab-ci.yml

@@ -30,6 +30,8 @@ stages:
 .setup:
   tags:
     - $DEFAULT_TAG
+  variables:
+    KUBERNETES_CPU_REQUEST: $CPU_REQUEST
   stage: build
   interruptible: true
   variables:
@@ -52,8 +54,6 @@ stages:
 # Generalised fragment to do a Kas build
 .build:
   extends: .setup
-  variables:
-    KUBERNETES_CPU_REQUEST: $CPU_REQUEST
   rules:
     # Don't run MR pipelines
     - if: $CI_PIPELINE_SOURCE == "merge_request_event"