chezmoi: manage ~/.config/sketchybar as symlink into repo

The old target was a symlink to ~/Git/my-configs/sketchybar, which
dangled after the repo moved to ~/.local/share/chezmoi, so sketchybar
started with an empty bar. A symlink_ entry keeps the plugins' exec
bits, which chezmoi drops when copying via source-side symlinks.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

Author: stanfish06

home-chezmoi/dot_config/symlink_sketchybar.tmpl

@@ -0,0 +1 @@
+{{ .chezmoi.workingTree }}/sketchybar