build: Add annotation to dist_Scripts and install_scripts

mesonbuild/build.py

@@ -230,9 +230,9 @@ class Build:
         self.static_linker: PerMachine[StaticLinker] = PerMachine(None, None)
         self.subprojects = {}
         self.subproject_dir = ''
-        self.install_scripts = []
+        self.install_scripts: T.List['ExecutableSerialisation'] = []
         self.postconf_scripts: T.List['ExecutableSerialisation'] = []
-        self.dist_scripts = []
+        self.dist_scripts: T.List['ExecutableSerialisation'] = []
         self.install_dirs: T.List[InstallDir] = []
         self.dep_manifest_name: T.Optional[str] = None
         self.dep_manifest: T.Dict[str, T.Dict[str, T.Any]] = {}  # TODO: what should this dict be?