Changes
* Add support for custom build-prerequisites Dockerfile (260) slonopotamus
* Adjust UBT pre-build warmup so it is compatible with UE >= 5.0.2 (261) slonopotamus
* Warn users about 20GiB COPY Docker bug (255) slonopotamus
* Add support for Visual Studio 2022 (253) jonpas
* Extend CI test matrix with older supported environments (252) slonopotamus
* Build ue4-build-prerequisites as a poor-man's testing on CI (247) slonopotamus