ci: Add variable to force pipeline to run
For debugging CI it is often useful to be able to run a pipeline outside of the context of an MR. The GitLab project has a FORCE_GITLAB_CI
variable that forces a pipeline to run even when the workflow requirements are not met.
Add an equivalent FORCE_GITALY_CI
variable to allow us to manually run pipelines as needed.
Edited by Will Chandler (ex-GitLab)