build(deps): update httpx requirement in /tests/e2e

Updates the requirements on [httpx](https://github.com/encode/httpx) to permit the latest version.
- [Release notes](https://github.com/encode/httpx/releases)
- [Changelog](https://github.com/encode/httpx/blob/master/CHANGELOG.md)
- [Commits](encode/httpx@0.27.0...0.28.1)

---
updated-dependencies:
- dependency-name: httpx
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

tests/e2e/pyproject.toml

@@ -1,7 +1,7 @@
 [project]
 name = "src"
 version = "1.0.0"
-dependencies = ["pytest ~= 8.2.2","httpx ~= 0.27.0","playwright ~= 1.43.0","pytest-asyncio ~= 0.23.7"]
+dependencies = ["pytest ~= 8.2.2","httpx ~= 0.28.1","playwright ~= 1.43.0","pytest-asyncio ~= 0.23.7"]
 requires-python = "==3.12.4"
 authors = [{ name = "kshramt", email = "[email protected]" }]
 description = "Evidence Based Scheduling"