Get rid of all transport types and settle on Protobuf (#25)

* Get rid of all transport types and settle on Protobuf

hope i don't regret this

* Update Cargo.toml

* Update agent.py

python/djls/_typing.py

@@ -0,0 +1,12 @@
+from __future__ import annotations
+
+import sys
+
+if sys.version_info >= (3, 12):
+    from typing import override as typing_override
+else:
+    from typing_extensions import (
+        override as typing_override,  # pyright: ignore[reportUnreachable]
+    )
+
+override = typing_override