Solarmach

<!-- Release notes generated using configuration in .github/release.yml at v0.4.3 -->

What's Changed
* Move `backmapping` and `solar_diff_rot` from the `SolarMACH` object to the base package so that they can be used externally (fixes https://github.com/jgieseler/solarmach/issues/62).
* Create a new `backmapping_angle` function so that this calculation is now centralized (and not spread as multiple copies over the whole code).
* Introduce astropy.units to `backmapping`, `backmapping_angle`, and `solar_diff_rot`
* Extend docstrings (https://github.com/jgieseler/solarmach/issues/45)
* Fix pytest falling for PFSS figure comparison

**Full Changelog**: https://github.com/jgieseler/solarmach/compare/v0.4.2...v0.4.3

<!-- Release notes generated using configuration in .github/release.yml at v0.4.2 -->

What's Changed
* Ensure compatibility with sunpy 6.0 and numpy 2.0

**Full Changelog**: https://github.com/jgieseler/solarmach/compare/v0.4.1...v0.4.2

<!-- Release notes generated using configuration in .github/release.yml at v0.4.1 -->

What's Changed
* Fix how DataFrames are addressed in `get_sw_speed` so that the function won't fail in the future if the keys of the DataFrame change (https://github.com/jgieseler/solarmach/commit/7293b7fb46e0a2f22fb2f0b449965fed02ca5d37)
* Add Europa Clipper mission to list of supported spacecraft

**Full Changelog**: https://github.com/jgieseler/solarmach/compare/v0.4.0...v0.4.1

<!-- Release notes generated using configuration in .github/release.yml at v0.4.0 -->

What's Changed
* **Remove supported Python versions 3.8 & 3.9** (in alignment with latest `sunpy` versions)
* Extend supported Python versions to 3.10, 3.11, 3.12
* Use [sunkit-magex](https://pypi.org/project/sunkit-magex/) instead of [pfsspy](https://pypi.org/project/pfsspy/) for PFSS analysis (because the latter is discontinued)
* Unpin matplotlib version in requirements 57
* Remove astroquery from requirements 48

**Full Changelog**: https://github.com/jgieseler/solarmach/compare/v0.3.4...v0.4.0

<!-- Release notes generated using configuration in .github/release.yml at v0.3.4 -->

What's Changed
* Improve importing of `speasy` by disabling unused data providers before, which will speed up the initial automatic determination of solar wind speeds (using `get_sw_speed`)
* Improve handling of input date & time (using now `sunpy.time.parse_time` everywhere)
* Catch failing `get_horizons_coord`
* Adjust to upcoming Pandas changes
* Include real image tests
* Upgrade GitHub actions

**Full Changelog**: https://github.com/jgieseler/solarmach/compare/v0.3.3...v0.3.4

<!-- Release notes generated using configuration in .github/release.yml at v0.3.3 -->

What's Changed
* Bugfix: `get_sw_speed` has been fixed to work again for Solar Orbiter (due to some changed ID)
* Some internal changes in the pfsspy part

**Full Changelog**: https://github.com/jgieseler/solarmach/compare/v0.3.2...v0.3.3