Need to add %UserProfile%\.choosenim\toolchains\mingw64\bin to path for cpp

[hcorion]

Just setup Nim on Windows 11 with choosenim, and whenever I compiled a nim file with C++ (via nim cpp -r .\file.nim) it would fail with a libgcc_s_seh-1.dll not found error.
I realized it was because the mingw64 toolchain path was not added to my user path, only the nimble path got added.
FWIW compiling the file with nim c -r .\file.nim works fine, I only had the dll issue with cpp.

[dom96]

This is caused by nim-lang/Nim#19713.