gitlab-ci: Disable shallow clones
Previously we were passing `--unshallow` to `git fetch` in the linting rules to ensure that the base commit which we were linting with respect to was available. However, this breaks due to GitLab's re-use of working directories since `git fetch --unshallow` fails on a repository which is not currently shallow. Given that `git fetch --unshallow` circumvents the efficiencies provided by shallow clones anyways, let's just disable them entirely. There is no documented way to do disable shallow clones but on checking the GitLab implementation it seems that setting `GIT_DEPTH=0` should do the trick.
Showing with 5 additions and 9 deletions