CI/build should fail fast if no tags are available

This was reported a while ago... If you have a partial clone / a clone without tags / a repository that doesn't have tags, then the version file that's generated isn't compatible w/ the expectations of `version.py`:

version = '0.1.dev1+gedcff4f'

guess that is `setuptools_scm` not being able to determine the right version number.

possible reasons:
- you did not do a full git clone, but only fetched the latest state (thus it has not enough history information). a shallow clone will **not** work.
- you also need to check out the correct tag, e.g. `git checkout 1.2.0`
- the run `pip install -e .` and `borg -V` and it should tell `1.2.0`.

_Originally posted by @ThomasWaldmann in https://github.com/borgbackup/borg/issues/6510#issuecomment-1126679447_

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Today, builds take >5 mins to fail in CI which is a lot of time for practically no benefit (you can't access the compiled content, you're just wasting GitHub resources and a build slot)

Start by reproducing the no-tags and shallow-clone cases around `pip install -e .`, then inspect the generated version file and `version.py`. Done means CI detects unavailable tag information and fails before the five-minute build, with an actionable error instead of producing an unusable version.

Written by the indexing model from the issue text.