ci: Request 1.5 CPUs for each container

The cloud aarch64 build machine does not have enough resources to build
multiple versions at once.  Requesting multiple CPUs ensures that only
one build pod is scheduled at a time.  Since the node has 2 CPUs and
240m CPUs are taken by Longhorn, if we request 1500m CPUs, builds will
run sequentially.

ci/podTemplate.yaml

@@ -5,6 +5,9 @@ spec:
     - cat
     stdin: true
     tty: true
+    resources:
+      requests:
+        cpu: 1500m
     volumeMounts:
     - mountPath: /etc/ssh/ssh_known_hosts
       name: ssh-known-hosts