CMakeToolchain generator allows harcoded CMake cli generator

[uilianries]

Not documented, but a public parameter: generator

https://github.com/conan-io/conan/blob/1.52.0/conan/tools/cmake/toolchain/toolchain.py#L118

On CCI is not possible to use conf file, and some project only work with specific generators.

Master branch is target because is in production already.