This change will prompt the CI workflow to cancel a currently running
job, if a new push is sent in a PR. This should prevent duplicate jobs
running for the same PR simultaneously.
Signed-off-by: Gabriel Adrian Samfira <gsamfira@cloudbasesolutions.com>
Building for the branch push event causes two builds per PR and is not
needed anyway (we have nightly builds for the main branch).
Only consider PR events to trigger the CI build.
The SDK container does not exist for arm64 and is quite heavy. We
currently also resort to a unconditional rebuilding of mantle inside
the SDK.
Use the new mantle container image to run kola tests, and pin its
version through a text file that gets updated by GitHub Actions.
