Obliviate Autotools and NMAKE build files
Hi,
This PR is a followup to !925 (merged). Here I remove all remnants of the Autotools and NMAKE based build files, adjusting the jobs to point to Meson.
A couple convention issues with MSYS2 were also fixed, along with a workaround to a Cargo issue that occurs if the user has a .rustup
folder in their home: https://github.com/rust-lang/cargo/issues/10885