CI: use more gitlab.com runners (MR 5236)

We have access to the fancy runners since GitLab.com donate premium to
us. There's no downside to making the most of them while we can. We
don't depend on them, but they'll make our CI go zoom!

For the next few months until we migrate to self-hosted :D

Signed-off-by: Caleb Connolly <caleb@postmarketos.org>

.gitlab-ci.yml

@@ -124,6 +124,8 @@ mr-settings:
 # build changed aports
 .build:
   stage: build
+  tags:
+    - saas-linux-large-amd64
   rules:
     - if: $CI_PIPELINE_SOURCE == "merge_request_event" || $CI_COMMIT_REF_PROTECTED == "false"
   before_script:
@@ -149,6 +151,8 @@ build-x86:
 
 build-aarch64:
   extends: .build
+  tags:
+    - saas-linux-large-arm64
   script:
     - .ci/build-aarch64.sh