Merge v3 Development into `develop`

[RHammond2]

This PR brings develop up to date with the v3 development branch. This merge will therefore deprecate v2.x and make it an unsupported version, and align the development workflow with the contributor's guide.

[codecov-commenter]

Codecov Report

Attention: 1504 lines in your changes are missing coverage. Please review.

Comparison is base (10b9408) 66.93% compared to head (edc65e4) 65.48%. Report is 1 commits behind head on develop.

Files	Patch %	Lines
openoa/utils/plot.py	5.43%	487 Missing :warning:
openoa/utils/qa.py	11.65%	197 Missing :warning:
openoa/utils/downloader.py	0.00%	173 Missing :warning:
openoa/plant.py	75.61%	158 Missing :warning:
openoa/analysis/aep.py	82.59%	83 Missing :warning:
openoa/analysis/wake_losses.py	86.00%	70 Missing :warning:
openoa/analysis/turbine_long_term_gross_energy.py	75.49%	62 Missing :warning:
openoa/schema/schema.py	49.50%	51 Missing :warning:
openoa/analysis/yaw_misalignment.py	82.89%	39 Missing :warning:
openoa/schema/metadata.py	86.41%	39 Missing :warning:
... and 13 more

Additional details and impacted files

```diff @@ Coverage Diff @@ ## develop #261 +/- ## =========================================== - Coverage 66.93% 65.48% -1.46% =========================================== Files 24 29 +5 Lines 1830 4358 +2528 =========================================== + Hits 1225 2854 +1629 - Misses 605 1504 +899 ```

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