Disable ARM64 CI builds (no more ARM builders)

Comment out build jobs rather than deleting them — the ARM64 builders
are gone and there's no real use for fresh builds anymore. Keeping the
config visible in case a builder comes back later.

.gitlab-ci.yml

@@ -6,22 +6,22 @@ services:
 before_script:
   - docker login -u "$CI_REGISTRY_USER" -p "$CI_REGISTRY_PASSWORD" $CI_REGISTRY
 
-build-master:
-  stage: build
-  tags:
-    - arm64
-  script:
-    - docker build --pull -t "$CI_REGISTRY_IMAGE" .
-    - docker push "$CI_REGISTRY_IMAGE"
-  only:
-    - master
+#build-master:
+#  stage: build
+#  tags:
+#    - arm64
+#  script:
+#    - docker build --pull -t "$CI_REGISTRY_IMAGE" .
+#    - docker push "$CI_REGISTRY_IMAGE"
+#  only:
+#    - master
 
-build:
-  stage: build
-  tags:
-    - arm64
-  script:
-    - docker build --pull -t "$CI_REGISTRY_IMAGE:$CI_COMMIT_REF_SLUG" .
-    - docker push "$CI_REGISTRY_IMAGE:$CI_COMMIT_REF_SLUG"
-  except:
-    - master
+#build:
+#  stage: build
+#  tags:
+#    - arm64
+#  script:
+#    - docker build --pull -t "$CI_REGISTRY_IMAGE:$CI_COMMIT_REF_SLUG" .
+#    - docker push "$CI_REGISTRY_IMAGE:$CI_COMMIT_REF_SLUG"
+#  except:
+#    - master