Build Windows using cross compile, remove msys2 sources

[mkitti]

1. Remove msys2 sources
2. Add lib64 to FCFLAGS (for openssl)
3. Add lib64 to CFLAGS (for openssl)

[mkitti]

When I enable MPI I was getting an error when loading the JLL at runtime.

Mingw-w64 runtime failure:
32 bit pseudo relocation at 0000000007828E2C out of range, targeting 00007FFDE78BAD90, yielding the value 00007FFDE0091F60.

[10684] signal (22): SIGABRT
in expression starting at REPL[8]:1
crt_sig_handler at C:/workdir/src\signals-win.c:95
raise at C:\windows\System32\msvcrt.dll (unknown line)
abort at C:\windows\System32\msvcrt.dll (unknown line)
__report_error at /workspace/srcdir/mingw-w64-v11.0.1/mingw-w64-crt/crt\pseudo-reloc.c:157
do_pseudo_reloc at /workspace/srcdir/mingw-w64-v11.0.1/mingw-w64-crt/crt\pseudo-reloc.c:457 [inlined]
_pei386_runtime_relocator at /workspace/srcdir/mingw-w64-v11.0.1/mingw-w64-crt/crt\pseudo-reloc.c:501
__DllMainCRTStartup at /workspace/srcdir/mingw-w64-v11.0.1/mingw-w64-crt/crt\crtdll.c:170
RtlActivateActivationContextUnsafeFast at C:\windows\SYSTEM32\ntdll.dll (unknown line)
LdrGetProcedureAddressEx at C:\windows\SYSTEM32\ntdll.dll (unknown line)
LdrGetProcedureAddressEx at C:\windows\SYSTEM32\ntdll.dll (unknown line)
RtlSwitchedVVI at C:\windows\SYSTEM32\ntdll.dll (unknown line)
RtlGetFullPathName_UstrEx at C:\windows\SYSTEM32\ntdll.dll (unknown line)
RtlDosPathNameToNtPathName_U at C:\windows\SYSTEM32\ntdll.dll (unknown line)
LdrLoadDll at C:\windows\SYSTEM32\ntdll.dll (unknown line)
LoadLibraryExW at C:\windows\System32\KERNELBASE.dll (unknown line)
ijl_dlopen at C:/workdir/src\dlload.c:163
ijl_load_dynamic_library at C:/workdir/src\dlload.c:348
#dlopen#3 at .\libdl.jl:117
dlopen at .\libdl.jl:116

I believe we may have to follow a distinct procedure such as detailed here.
https://www.symscape.com/configure-msmpi-for-mingw-w64

For now, let's just disable Microsoft MPI