[gnome-builder] plugins/gjs-symbols: remove gjs-symbols plugin

[Christian Hergert <chergert src gnome org>]

commit 82ecb742332e3f5353259510dba07d80ef103a77
Author: Christian Hergert <chergert redhat com>
Date:   Mon Jul 11 22:48:29 2022 -0700

    plugins/gjs-symbols: remove gjs-symbols plugin
    
    This doesn't work anymore due to changes in GJS/SpiderMonkey. We can
    probably get the feature another way using the typescript-language-server
    if someone spends time on it.

 src/plugins/gjs-symbols/gjs_symbols.plugin |  13 -
 src/plugins/gjs-symbols/gjs_symbols.py     | 463 -----------------------------
 src/plugins/gjs-symbols/meson.build        |  13 -
 3 files changed, 489 deletions(-)