Docs: Recommend using bound function reference instead of watch=True in bind_component guide - #8479

Description

Fixes #6271

This PR updates the documentation in doc/how_to/interactivity/bind_component.md to clarify the recommended pattern for using pn.bind when updating component parameters.

Users coming from param.watch() patterns may attempt to use watch=True with pn.bind. However, this pattern recreates the object whenever the inputs change and is generally considered an anti-pattern.

This PR adds a section explaining that a better approach is to assign the bound function directly to the relevant component parameter. For example:

def update_value(select_value, slider_value):
    return select_value * slider_value

text = pn.widgets.StaticText(value=pn.bind(update_value, select, slider))

This approach keeps the component reactive while avoiding unnecessary object recreation and ensures that only the relevant parameter is updated.

The documentation change clarifies the intended usage of pn.bind and improves guidance for users working with reactive components.

How Has This Been Tested?

This change only modifies documentation.

The updated section was reviewed locally to ensure:

• Correct Markdown formatting
• Proper placement within the existing guide
• Consistency with surrounding documentation examples

Since this is a documentation-only change, no runtime functionality or tests were affected.

AI Disclosure

• This PR contains AI-generated content.
• I have tested all AI-generated content in my PR.
• I take responsibility for all AI-generated content in my PR.

Tools: ChatGPT

Checklist

• Tests added and is passing
• Added documentation