Allow failure of the ARM CI job as long as the runner is unstable

.gitlab-ci.yml

@@ -9,11 +9,13 @@ test-linux-x64:
     - ./generic/setup.sh clean-bundle-complete linux x64
     - ./generic/fetch.sh clean-bundle-complete linux x64
     - ./generic/build.sh clean-bundle-complete linux x64
+
 test-linux-arm64:
   tags:
       - arm64
       - linux
   image: ubuntu
+  allow_failure: true # the arm runner is unreliable
   before_script:
     - apt-get update -qq
     - apt-get install -qq gcc make subversion git ca-certificates curl unzip