interpreter: use typed_kwargs for build_target.install_rpath

mesonbuild/interpreter/kwargs.py

@@ -330,6 +330,7 @@ class _BaseBuildTarget(TypedDict):
     extra_files: T.List[FileOrString]
     install: bool
     install_mode: FileMode
+    install_rpath: str
     implicit_include_directories: bool
     native: MachineChoice
     override_options: T.Dict[OptionKey, T.Union[str, int, bool, T.List[str]]]

mesonbuild/interpreter/type_checking.py

@@ -577,6 +577,7 @@ _BUILD_TARGET_KWS: T.List[KwargInfo] = [
         since='1.2.0',
     ),
     KwargInfo('build_rpath', str, default='', since='0.42.0'),
+    KwargInfo('install_rpath', str, default=''),
 ]
 
 def _validate_win_subsystem(value: T.Optional[str]) -> T.Optional[str]: