git describe is used for version string creation, but it had to be
reverted in commit 69da6ba because it was broken in CI builds.
Azure Pipelines and Drone perform shallow clones by default.
This change reconfigures them to fetch history and tags. It adds tens of
seconds, which is negligible compared to overall build and test time.
Related: #6466, #6509, #7601
We're up against the 6 hour limit so this is a time-saving workaround.
Compile error tests are generally not OS-specific so the coverage from
the other platforms should be sufficient.
