This PR renames the UI names of EEVEE render engines, due to the decision to
postpone EEVEE-Next to Blender 4.2.
* `EEVEE` is now named `EEVEE-Next`.
* `EEVEE (Legacy)` is now named `EEVEE`.
Pull Request: https://projects.blender.org/blender/blender/pulls/117437