chore(deps): update logfire[fastapi,httpx,system-metrics] requirement

Updates the requirements on [logfire[fastapi,httpx,system-metrics]](https://github.com/pydantic/logfire) to permit the latest version.
- [Release notes](https://github.com/pydantic/logfire/releases)
- [Changelog](https://github.com/pydantic/logfire/blob/main/CHANGELOG.md)
- [Commits](pydantic/logfire@v2.7.0...v2.8.0)

---
updated-dependencies:
- dependency-name: logfire[fastapi,httpx,system-metrics]
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

pyproject.toml

@@ -21,7 +21,7 @@ dependencies = [
     "zhipuai~=2.1.5.20241203",
     "anthropic~=0.40.0",
     "dashscope~=1.20.2",
-    "logfire[fastapi,system-metrics,httpx]~=2.7.0",
+    "logfire[fastapi,system-metrics,httpx]~=2.8.0",
 ]
 
 [tool.pdm]