Use static msvc runtime.

It's not worth the trouble of dealing with the dynamic msvc runtime. Especially all the times AZP and GHA forget to properly install VS updates and break dynamic linking. So stay with the larger binary sizes and static runtime.

src/engine/config_toolset.bat

@@ -156,7 +156,7 @@ REM return to current directory as vsdevcmd_end.bat switches to %USERPROFILE%\So
 pushd %CD%
 if "_%VSINSTALLDIR%_" == "__" call :Call_If_Exists "%B2_TOOLSET_ROOT%Auxiliary\Build\vcvarsall.bat" %B2_BUILD_ARGS%
 popd
-set "B2_CXX="%CXX%" /nologo /MD /TP /Feb2 /wd4996 /wd4675 /Ox /GL /EHsc /Zc:wchar_t /Gw"
+set "B2_CXX="%CXX%" /nologo /MP /MT /TP /Feb2 /wd4996 /wd4675 /Ox /GL /EHsc /Zc:wchar_t /Gw"
 set "B2_CXX_LINK=/link kernel32.lib advapi32.lib user32.lib"
 set "_known_=1"
 goto :Embed_Minafest_Via_Link