Windows Build: Why does the windows build guide instructs to add "mingw64/bin" to ~/.bash_profile?

The guide already tells us to run "MSYS2 MINGW64" shell. That one already has "mingw64/bin" in the PATH.
Additionally adding "mingw64/bin" to ~/.bash_profile potentially breaks other msys2 shells/toolchains, as it's loaded in all of them.

Maybe instead of poluting the global ~/.bash_profile, the project can use a .bat file that adds the necessary envars and loads the correct shell?

Locate the Windows build guide and review its instructions for the MSYS2 MINGW64 shell and ~/.bash_profile. Confirm whether the global PATH change is needed, then update the documented setup or provide the proposed shell-loading approach; done means the guide avoids unintended changes to other MSYS2 toolchains.

Written by the indexing model from the issue text.