[vte] bindings: vala: Remove the test app

[Christian Persch <chpe src gnome org>]

commit 9a3769b22da64a040f8ab306f25cecc3e25e2305
Author: Christian Persch <chpe src gnome org>
Date:   Fri Apr 8 21:50:18 2022 +0200

    bindings: vala: Remove the test app
    
    It only existed anymore to test that comping a vala programme with the
    vte vapi works, but it's been broken by vala changes a couple of times,
    and also is too much work to port to gtk4.  So just remove it.

 bindings/vala/app.gresource.xml |   23 -
 bindings/vala/app.ui            |  152 ------
 bindings/vala/app.vala          | 1099 ---------------------------------------
 bindings/vala/config.vapi       |    5 -
 bindings/vala/search-popover.ui |  249 ---------
 5 files changed, 1528 deletions(-)