Synchronization between `2.x` and `main`

This meta-issue lists the PRs or modifications that didn't make it to `main` yet. Feel free to modify it after each merged PR that you don't have time or can not port immediately:

- [ ] #2716
- [ ] #2962
- [x] #3055
- [x] #3052
- [x] #3118
- [ ] #3158
- [x] #3133
- [x] #3175 (not needed before first `3.0.0` release)
- [x] #3226
- [ ] #3195
- [x] #3338
- [x] #3259
- [x] #3260
- [x] #3265
- [ ] #3217 (documentation part)
- [ ] #3381
- [ ] #3418
- [x] #3438
- [x] #3469
- [ ] #3467
- [x] https://github.com/apache/logging-log4j2/commit/e9168137ab4463013aa8d3007812b4a1cf569dac
- [ ] #4184

Ported PRs:
- [ ] #3583
- [x] #3584
- [x] #3586
- [ ] #3171
- [x] #3372
- [x] #3322