[Bug] Problems with di built-in generics

[owakira]

Describe the bug
I found an interesting bug: di doesn't work with built-in generics.

class Client:
    pass


class Service:
    def __init__(self, clients: list[Client]) -> None:
        self._clients = clients


def _get_clients() -> list[Client]:
    return [Client() for _ in range(3)]


def configure_di(app: Sanic) -> None:
    app.ext.add_dependency(list[Client], _get_clients)
    app.ext.add_dependency(Service)

It throws the following error:

File "/usr/local/lib/python3.11/site-packages/sanic_ext/extensions/injection/injector.py", line 37, in finalize_injections
    injection_registry.finalize(app, constant_registry, router_types)
File "/usr/local/lib/python3.11/site-packages/sanic_ext/extensions/injection/registry.py", line 42, in finalize
    constructor.prepare(
File "/usr/local/lib/python3.11/site-packages/sanic_ext/extensions/injection/constructor.py", line 111, in prepare
    raise InitError(
sanic_ext.exceptions.InitError: Unable to resolve dependencies for 'Service'. Could not find the following dependencies:
  - clients: list[src.di.Client].
Make sure the dependencies are declared using ext.injection. See https://sanicframework.org/en/plugins/sanic-ext/injection.html#injecting-services for more details.
Not all workers acknowledged a successful startup. Shutting down.

Environment (please complete the following information):

• OS: [e.g. Ubuntu] MacOS Sequoia
• Version [e.g. 0.5.3] Python 3.11, sanic 22.12.0, sanic-ext 23.6.0

[owakira]

I found the issue in sanic_ext/extensions/injection/constructor.py:

if not isclass(annotation):
    missing.append((param, annotation))
    continue

The condition for list[Client] will always be True.
It is necessary to add a new check for built-in generics.

[owakira]

Created pull request
#263