TST: fix test package default options to allow compilation with MSVC

Meson by default derives the Microsoft runtime library to use from the
build type, see the documentation for the b_vscrt base option
https://mesonbuild.com/Builtin-options.html#base-options

The default build type is debug, which causes a debug version og the
runtime library to be used. This in turn causes the linker to look
for debug version of the linked DLLs. Python does not distribute a
debug version of the pythonXY.dll thus the linking fails.

Set the build type for the test package to release to fix the issue.

tests/packages/detect-compiler/meson.build

@@ -6,6 +6,9 @@ project(
     'detect-compiler',
     'c',
     version: '1.0',
+    default_options: [
+        'buildtype=release'
+    ]
 )
 
 py = import('python').find_installation()