<!-- Release notes generated using configuration in .github/release.yml at main -->
What's Changed
Maintenance
* Remove remnants of prefect by oyvindeide in https://github.com/equinor/ert/pull/5689
* Inline test data in tests by oyvindeide in https://github.com/equinor/ert/pull/5693
Other Changes
* Rename parameter save and load functions by oyvindeide in https://github.com/equinor/ert/pull/5471
* Change init for genKw by frode-aarstad in https://github.com/equinor/ert/pull/5637
* Only write mask to experiment, not full grid by oyvindeide in https://github.com/equinor/ert/pull/5665
* Remove C code from `res_utils` by pinkwah in https://github.com/equinor/ert/pull/5691
* Remove unused test-data directory by oyvindeide in https://github.com/equinor/ert/pull/5690
* Remove unused C test data by pinkwah in https://github.com/equinor/ert/pull/5692
* Fix bug in es-mda where returned variable could potentially be unbound by oyvindeide in https://github.com/equinor/ert/pull/5683
New Contributors
* kwinkunks made their first contribution in https://github.com/equinor/ert/pull/4994
**Full Changelog**: https://github.com/equinor/ert/compare/5.1.0-b1...5.1.0-b2