[CI] Add Cirrus builds

[codecov[bot]]

Codecov Report

Base: 97.81% // Head: 97.82% // Increases project coverage by +0.00% :tada:

Coverage data is based on head (6dd07e7) compared to base (fef66fb). Patch has no changes to coverable lines.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #68 +/- ## ======================================= Coverage 97.81% 97.82% ======================================= Files 3 4 +1 Lines 366 367 +1 ======================================= + Hits 358 359 +1 Misses 8 8 ``` | [Impacted Files](https://codecov.io/gh/bbopt/NOMAD.jl/pull/68?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=None) | Coverage Δ | | |---|---|---| | [src/NOMAD.jl](https://codecov.io/gh/bbopt/NOMAD.jl/pull/68/diff?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=None#diff-c3JjL05PTUFELmps) | `100.00% <0.00%> (ø)` | | Help us with your feedback. Take ten seconds to tell us [how you rate us](https://about.codecov.io/nps?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=None). Have a feature suggestion? [Share it here.](https://app.codecov.io/gh/feedback/?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=None)

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