Python: fix limited API logic under mingw

The Python Limited API support that was added in 1.2 had
special handling of Windows, but the condition to check for
Windows was not correct: it checked for MSVC and not for
the target's OS. This causes mingw installations to not have
the special handling applied.

This commit fixes this to check explicitly for Windows.

mesonbuild/modules/python.py

@@ -184,13 +184,9 @@ class PythonInstallation(_ExternalProgramHolder['PythonExternalProgram']):
             new_cpp_args.append(limited_api_definition)
             kwargs['cpp_args'] = new_cpp_args
 
-            # When compiled under MSVC, Python's PC/pyconfig.h forcibly inserts pythonMAJOR.MINOR.lib
-            # into the linker path when not running in debug mode via a series #pragma comment(lib, "")
-            # directives. We manually override these here as this interferes with the intended
-            # use of the 'limited_api' kwarg
+            # On Windows, the limited API DLL is python3.dll, not python3X.dll.
             for_machine = kwargs['native']
-            compilers = self.interpreter.environment.coredata.compilers[for_machine]
-            if any(compiler.get_id() == 'msvc' for compiler in compilers.values()):
+            if self.interpreter.environment.machines[for_machine].is_windows():
                 pydep_copy = copy.copy(pydep)
                 pydep_copy.find_libpy_windows(self.env, limited_api=True)
                 if not pydep_copy.found():
@@ -199,6 +195,12 @@ class PythonInstallation(_ExternalProgramHolder['PythonExternalProgram']):
                 new_deps.remove(pydep)
                 new_deps.append(pydep_copy)
 
+            # When compiled under MSVC, Python's PC/pyconfig.h forcibly inserts pythonMAJOR.MINOR.lib
+            # into the linker path when not running in debug mode via a series #pragma comment(lib, "")
+            # directives. We manually override these here as this interferes with the intended
+            # use of the 'limited_api' kwarg
+            compilers = self.interpreter.environment.coredata.compilers[for_machine]
+            if any(compiler.get_id() == 'msvc' for compiler in compilers.values()):
                 pyver = pydep.version.replace('.', '')
                 python_windows_debug_link_exception = f'/NODEFAULTLIB:python{pyver}_d.lib'
                 python_windows_release_link_exception = f'/NODEFAULTLIB:python{pyver}.lib'