Update gradio-client requirement from <1.5 to <1.6 in /framework/gradio

Updates the requirements on [gradio-client](https://github.com/gradio-app/gradio) to permit the latest version.
- [Release notes](https://github.com/gradio-app/gradio/releases)
- [Changelog](https://github.com/gradio-app/gradio/blob/main/CHANGELOG.md)
- [Commits](https://github.com/gradio-app/gradio/compare/@self/[email protected][email protected])

---
updated-dependencies:
- dependency-name: gradio-client
  dependency-type: direct:development
...

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

framework/gradio/requirements-dev.txt

@@ -1,2 +1,2 @@
-gradio-client<1.5
+gradio-client<1.6
 pytest<9