ci: re-enable freebsd coverage

[codecov[bot]]

Codecov Report

Patch coverage: 50.00% and project coverage change: +0.02% :tada:

Comparison is base (197537d) 88.79% compared to head (126cd6e) 88.81%.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #143 +/- ## ========================================== + Coverage 88.79% 88.81% +0.02% ========================================== Files 14 14 Lines 1669 1672 +3 ========================================== + Hits 1482 1485 +3 Misses 187 187 ``` | [Flag](https://app.codecov.io/gh/Smithay/calloop/pull/143/flags?src=pr&el=flags&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Smithay) | Coverage Δ | | |---|---|---| | [macos-latest](https://app.codecov.io/gh/Smithay/calloop/pull/143/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Smithay) | `88.49% <50.00%> (ø)` | | | [ubuntu-latest](https://app.codecov.io/gh/Smithay/calloop/pull/143/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Smithay) | `88.38% <50.00%> (ø)` | | Flags with carried forward coverage won't be shown. [Click here](https://docs.codecov.io/docs/carryforward-flags?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Smithay#carryforward-flags-in-the-pull-request-comment) to find out more. | [Files Changed](https://app.codecov.io/gh/Smithay/calloop/pull/143?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Smithay) | Coverage Δ | | |---|---|---| | [src/sources/generic.rs](https://app.codecov.io/gh/Smithay/calloop/pull/143?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Smithay#diff-c3JjL3NvdXJjZXMvZ2VuZXJpYy5ycw==) | `78.87% <50.00%> (ø)` | | ... and [1 file with indirect coverage changes](https://app.codecov.io/gh/Smithay/calloop/pull/143/indirect-changes?src=pr&el=tree-more&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Smithay)

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.