Fix gfortran 11 linking issue on Windows (#58)

Programs compiled with gfortran 11 on Windows could link against the libgfortran-5.dll found in /c/mingw64/bin, which is associated with gfortran 12 (installed by default on Windows 2022 runner image). The simple solution is to move the entire mingw64 folder instead of just a few files.

Author: nbelakovski

setup-fortran.sh

@@ -98,10 +98,7 @@ install_gcc_choco()
     echo "GCC $version already installed"
   else
     # otherwise hide preinstalled mingw compilers
-    mkdir "$RUNNER_TEMP/mingw64"
-    mv /c/mingw64/bin/gfortran "$RUNNER_TEMP/mingw64/gfortran"
-    mv /c/mingw64/bin/gcc "$RUNNER_TEMP/mingw64/gcc"
-    mv /c/mingw64/bin/g++ "$RUNNER_TEMP/mingw64/g++"
+    mv /c/mingw64 "$RUNNER_TEMP/"
     # ...and install selected version
     case $version in
       13)