modules/gnome: fix type annotations from `__init__`, which are wrong

Mainly thi sis that `state.find_program()` is annotated incorrectly, it
returns `ExternalProgram | Executable | OverrideProgram`, but it's
annotated to return only `ExteranlProgram`, and thus a bunch of the
annotations in the gnome module are wrong.

mesonbuild/modules/gnome.py

@@ -403,7 +403,7 @@ class GnomeModule(ExtensionModule):
         glib_version = self._get_native_glib_version(state)
 
         glib_compile_resources = state.find_program('glib-compile-resources')
-        cmd: T.List[T.Union[ExternalProgram, str]] = [glib_compile_resources, '@INPUT@']
+        cmd: T.List[T.Union[ExternalProgram, Executable, OverrideProgram, str]] = [glib_compile_resources, '@INPUT@']
 
         source_dirs = kwargs['source_dir']
         dependencies = kwargs['dependencies']
@@ -493,7 +493,7 @@ class GnomeModule(ExtensionModule):
             raise MesonException('GResource header is installed yet export is not enabled')
 
         depfile: T.Optional[str] = None
-        target_cmd: T.List[T.Union[ExternalProgram, str]]
+        target_cmd: T.List[T.Union[ExternalProgram, Executable, OverrideProgram, str]]
         if not mesonlib.version_compare(glib_version, gresource_dep_needed_version):
             # This will eventually go out of sync if dependencies are added
             target_cmd = cmd
@@ -1232,7 +1232,7 @@ class GnomeModule(ExtensionModule):
         srcdir = os.path.join(state.build_to_src, state.subdir)
         outdir = state.subdir
 
-        cmd: T.List[T.Union[ExternalProgram, str]] = [state.find_program('glib-compile-schemas'), '--targetdir', outdir, srcdir]
+        cmd: T.List[T.Union[ExternalProgram, Executable, OverrideProgram, str]] = [state.find_program('glib-compile-schemas'), '--targetdir', outdir, srcdir]
         if state.subdir == '':
             targetname = 'gsettings-compile'
         else:
@@ -1311,7 +1311,7 @@ class GnomeModule(ExtensionModule):
 
         pot_file = os.path.join('@SOURCE_ROOT@', state.subdir, 'C', project_id + '.pot')
         pot_sources = [os.path.join('@SOURCE_ROOT@', state.subdir, 'C', s) for s in sources]
-        pot_args: T.List[T.Union['ExternalProgram', str]] = [itstool, '-o', pot_file]
+        pot_args: T.List[T.Union[ExternalProgram, Executable, OverrideProgram, str]] = [itstool, '-o', pot_file]
         pot_args.extend(pot_sources)
         pottarget = build.RunTarget(f'help-{project_id}-pot', pot_args, [],
                                     os.path.join(state.subdir, 'C'), state.subproject,
@@ -1340,7 +1340,7 @@ class GnomeModule(ExtensionModule):
                 targets.append(l_data)
 
             po_file = l + '.po'
-            po_args: T.List[T.Union['ExternalProgram', str]] = [
+            po_args: T.List[T.Union[ExternalProgram, Executable, OverrideProgram, str]] = [
                 msgmerge, '-q', '-o',
                 os.path.join('@SOURCE_ROOT@', l_subdir, po_file),
                 os.path.join('@SOURCE_ROOT@', l_subdir, po_file), pot_file]
@@ -1462,6 +1462,7 @@ class GnomeModule(ExtensionModule):
             program_name = 'gtkdoc-' + tool
             program = state.find_program(program_name)
             path = program.get_path()
+            assert path is not None, "This shouldn't be possible since program should be found"
             t_args.append(f'--{program_name}={path}')
         if namespace:
             t_args.append('--namespace=' + namespace)
@@ -1596,7 +1597,7 @@ class GnomeModule(ExtensionModule):
                       kwargs: 'GdbusCodegen') -> ModuleReturnValue:
         namebase = args[0]
         xml_files: T.List[T.Union['FileOrString', build.GeneratedTypes]] = [args[1]] if args[1] else []
-        cmd: T.List[T.Union['ExternalProgram', str]] = [state.find_program('gdbus-codegen')]
+        cmd: T.List[T.Union[ExternalProgram, Executable, OverrideProgram, str]] = [state.find_program('gdbus-codegen')]
         cmd.extend(kwargs['extra_args'])
 
         # Autocleanup supported?
@@ -1914,7 +1915,7 @@ class GnomeModule(ExtensionModule):
             install_dir: T.Optional[T.Sequence[T.Union[str, bool]]] = None,
             depends: T.Optional[T.Sequence[T.Union[CustomTarget, CustomTargetIndex, BuildTarget]]] = None
             ) -> build.CustomTarget:
-        real_cmd: T.List[T.Union[str, ExternalProgram]] = [state.find_program(['glib-mkenums', 'mkenums'])]
+        real_cmd: T.List[T.Union[ExternalProgram, Executable, OverrideProgram, str]] = [state.find_program(['glib-mkenums', 'mkenums'])]
         real_cmd.extend(cmd)
         _install_dir = install_dir or state.environment.coredata.get_option(mesonlib.OptionKey('includedir'))
         assert isinstance(_install_dir, str), 'for mypy'
@@ -1958,7 +1959,7 @@ class GnomeModule(ExtensionModule):
 
         new_genmarshal = mesonlib.version_compare(self._get_native_glib_version(state), '>= 2.53.3')
 
-        cmd: T.List[T.Union['ExternalProgram', str]] = [state.find_program('glib-genmarshal')]
+        cmd: T.List[T.Union[ExternalProgram, Executable, OverrideProgram, str]] = [state.find_program('glib-genmarshal')]
         if kwargs['prefix']:
             cmd.extend(['--prefix', kwargs['prefix']])
         if kwargs['extra_args']:
@@ -2103,7 +2104,7 @@ class GnomeModule(ExtensionModule):
         build_dir = os.path.join(state.environment.get_build_dir(), state.subdir)
         source_dir = os.path.join(state.environment.get_source_dir(), state.subdir)
         pkg_cmd, vapi_depends, vapi_packages, vapi_includes, packages = self._extract_vapi_packages(state, kwargs['packages'])
-        cmd: T.List[T.Union[str, 'ExternalProgram']]
+        cmd: T.List[T.Union[ExternalProgram, Executable, OverrideProgram, str]]
         cmd = [state.find_program('vapigen'), '--quiet', f'--library={library}', f'--directory={build_dir}']
         cmd.extend([f'--vapidir={d}' for d in kwargs['vapi_dirs']])
         cmd.extend([f'--metadatadir={d}' for d in kwargs['metadata_dirs']])