refactor: revert to typing-extensions library (#333)

Revert to using the typing-extensions package since it performs the same
logic introduced in the `_typing_extensions.py` module copied from
Shiny. For example, here is the `Self` implementation in
typing-extensions, which keys off of the python version to determine the
correct import.
https://github.com/python/typing_extensions/blob/main/src/typing_extensions.py#L2229-L2247

src/posit/connect/content.py

@@ -15,9 +15,10 @@
     overload,
 )
 
+from typing_extensions import NotRequired, Required, TypedDict, Unpack
+
 from . import tasks
 from ._api import ApiDictEndpoint, JsonifiableDict
-from ._typing_extensions import NotRequired, Required, TypedDict, Unpack
 from .bundles import Bundles
 from .context import Context
 from .env import EnvVars

src/posit/connect/jobs.py

@@ -1,7 +1,8 @@
 import posixpath
 from typing import Any, Literal, Optional, overload
 
-from ._typing_extensions import NotRequired, Required, TypedDict, Unpack
+from typing_extensions import NotRequired, Required, TypedDict, Unpack
+
 from .context import Context
 from .resources import Active, ActiveFinderMethods, ActiveSequence, Resource
 

src/posit/connect/oauth/oauth.py

@@ -2,7 +2,8 @@
 
 from typing import Optional
 
-from .._typing_extensions import TypedDict
+from typing_extensions import TypedDict
+
 from ..resources import ResourceParameters, Resources
 from .integrations import Integrations
 from .sessions import Sessions

src/posit/connect/users.py

@@ -4,8 +4,9 @@
 
 from typing import List, Literal
 
+from typing_extensions import NotRequired, Required, TypedDict, Unpack
+
 from . import me
-from ._typing_extensions import NotRequired, Required, TypedDict, Unpack
 from .content import Content
 from .paginator import Paginator
 from .resources import Resource, ResourceParameters, Resources

src/posit/connect/vanities.py

@@ -1,6 +1,7 @@
 from typing import Callable, List, Optional
 
-from ._typing_extensions import NotRequired, Required, TypedDict, Unpack
+from typing_extensions import NotRequired, Required, TypedDict, Unpack
+
 from .errors import ClientError
 from .resources import Resource, ResourceParameters, Resources