Add size metric report

See also https://docs.gitlab.com/ee/ci/metrics_reports.html
3 jobs for add-size-metrics in 26 minutes and 38 seconds (queued for 2 seconds)
Status Name Job ID Coverage
  Lint
passed shellcheck #5035

00:00:16

passed shfmt #5036

00:00:11

 
  Build
passed build #5037

00:26:22