CI: Try without RVM on ARM Linux

Does this help us with our TLS/SSL error woes in CI on ARM Linux?

.cirrus.yml

@@ -79,11 +79,6 @@ arm_linux_task:
                 libasound2-dev
                 libnss3
                 xvfb
-    - gpg2 --recv-keys 409B6B1796C275462A1703113804BB82D39DC0E3 7D2BAF1CF37B13E2069D6956105BD0E739499BDB
-    - \curl -sSL https://get.rvm.io | bash -s stable
-    - source /etc/profile.d/rvm.sh
-    - rvm install ruby
-    - gem install fpm
     - git submodule init
     - git submodule update
     - sed -i -e "s/[0-9]*-dev/`date -u +%Y%m%d%H`/g" package.json
@@ -93,7 +88,6 @@ arm_linux_task:
     - yarn build
     - yarn run build:apm
   build_binary_script:
-    - source /etc/profile.d/rvm.sh
     - yarn dist || yarn dist
   binary_artifacts:
     path: ./binaries/*