#247

perf: optimize git-gutter:view-for-unchanged with range-based processing

Bump actions/checkout from 4 to 5

Add staged-sign (git diff --cached)

Allow killing indirect when base buffer has already been killed.

Change `when-let` to `when-let*` since it will be obsolete by emacs31

Use window-buffer-change-function hook

Emacs 29 build fix

Add remote flag to `executable-find`

Removed `executable-find`