Updates for py-shiny v0.7.0

[gadenbuie]

• Add input_task_button, an actionButton with busy state
• Add input_task_button to pkgdown, remove cruft
• Remove more cruft
• Refactor task button
• Automatic reset of task button after reactive flush
• Fix devtools::load_all("shiny")
• Add input_task_button() item to NEWS
• Code review feedback
• Apply suggestions from code review
• More code review feedback
• Move shiny::bind_task_to_button to bslib::bind_task_button generic
• Add example for bind_task_button
• Add future to Suggests, only because it's used in a new example
• Put task button's unnamed ... inside of
• Fix comment
• Use correct JSON member name
• Code review feedback
• Use @examplesIf interactive()
• Make CI pass, hopefully
• devtools::document() (GitHub Actions)
• Don't error on repeated load_all
• Add bind_task_button to index
• Add note to docs
• Fix example for R <4.1
• fix(layout_columns): Don't break grid-column on md-down (fix(layout_columns): Don't break grid-column on md-down #970)

[gadenbuie]

I made the PR to have CI build our component assets, but that won't work because there are conflicts with main and the PR is merged into main anyway when the assets are created. I'll do it manually and locally instead.