packaging: require typing-extensions 4.x (#1257)

## Summary
- require `typing-extensions>=4.0.0,<5.0.0` because the SDK imports
`Self`
- update the lockfile metadata for the declared runtime constraint

## Testing
- built the wheel and verified its `Requires-Dist` metadata
- installed the wheel with the minimum `typing-extensions==4.0.0` and
imported every SDK module that uses `Self`, `ParamSpec`, or `TypedDict`
- `uv lock --check`

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: cartertinney

pyproject.toml

@@ -32,7 +32,7 @@ dependencies = [
     "PySocks",
     "requests>=2.32.3,<3.0.0",
     "requests-unixsocket>=0.4.1",
-    "typing-extensions",
+    "typing-extensions>=4.0.0,<5.0.0",
 ]
 
 [project.urls]