build(deps): bump panel from 1.4.2 to 1.4.3 in /requirements

Bumps [panel](https://github.com/holoviz/panel) from 1.4.2 to 1.4.3.
- [Release notes](https://github.com/holoviz/panel/releases)
- [Changelog](https://github.com/holoviz/panel/blob/main/CHANGELOG.md)
- [Commits](holoviz/panel@v1.4.2...v1.4.3)

---
updated-dependencies:
- dependency-name: panel
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

requirements/requirements_doc.txt

@@ -21,5 +21,5 @@ sphinx-autobuild==2024.4.16
 sphinx-autodoc-typehints==2.1.0
 sphinx-design==0.5.0
 sphinx-notfound-page==1.0.0
-panel==1.4.2
+panel==1.4.3
 pypandoc==1.13