Add CHANGELOG for 1.5.1

[philippjfr]

This release primarily focuses on a number of tweaks and enhancements for the documentation and also resolves a number of bugs related to Tabulator rendering and the new FastAPI integration. As always, many thanks to our contributors including our new contributors @dennisjlee and @alexcjohnson, our returning contributors @thuydotm and @jbednar and the core maintainer team @hoxbro, @maximlt, @ahuang11, @MarcSkovMadsen and @philippjfr.

Enhancements

• Add mapboxgl CSS to Plotly (#7320)
• Tweak margins of icons in ChatMessage (#7310)

Bug fixes

• Fix langchain import in panel.chat.langchain (#7297)
• Ensure Tabulator is consistently redrawn after render and resize (#7305)
• Filter out empty plotly_selected events (#7312)
• Improve parameter validation on Timepicker (#7308)
• Ensure Tabulator.selection consistency when pagination='local' (#7304)
• Correctly handle ipv6 localhost URI in Location (#7316)
• Ensure resource URLs are handled correctly in all server implementations (#7318)
• Ensure Plotly datetime are correctly converted from timestamp to date string (#7319)

Regressions

• Only postpone --setup script until after server startup if --num-procs is greater than 1 (#7289)

Documentation

• Fix and improve JupyterLite pyodide distribution (#7286)
• Document how to apply gradient styling o Tabulator cells (#7291)
• Clarified wording in best practices docs (#7290)
• Minor tweaks for the FileDropper (#7307)
• Ensure docs consistently recommend --dev over --autoreload (#7285)
• Tweaks for Tabulator docs (#7315)
• Improve fastapi docs (#7317)
• Add note about Tabulator font-size (#7321)
• Tweak best practices (#7301)
• Fix typo in JPG component docs (#7323)