global config option to set default "Custom CI config path"
Description
I'm working on getting CI/CD working well on the new, official Debian gitlab: https://salsa.debian.org. Its pretty close to working quite well, but there is one small detail: the default location for .gitlab-ci.yml does not work for the vast majority of Debian's almost 50,000 packages. Most packages in Debian are "non-native" packages, e.g. the source is not maintained in Debian, only the packaging parts. The git repos for non-native packages only allow modifications in the debian/ sub-directory. Anything in the root directory is considered part of the original, upstream source for the package.
Switching the "Custom CI config path" preference to debian/.gitlab-ci.yml works fine, so this should be the default for Debian's gitlab. As far as I can tell, there is no way to set this default right now.
Proposal
Add global config option so that the gitlab admin can set the default for "Custom CI config path" to something besides .gitlab-ci.yml in the root of the project.