[master] c7e93010a doc: Add a definition for VUT in VTLA

[Dridi Boukelmoune]

commit c7e93010aa5b743ebbb8d6a6b09dcf196b63acc8
Author: Audun-Marius Gangstø <audun at gangsto.org>
Date:   Wed May 21 18:05:41 2025 +0200

    doc: Add a definition for VUT in VTLA

diff --git a/doc/sphinx/reference/vtla.rst b/doc/sphinx/reference/vtla.rst
index e155926c2..9bf19e603 100644
--- a/doc/sphinx/reference/vtla.rst
+++ b/doc/sphinx/reference/vtla.rst
@@ -122,6 +122,9 @@ VUG
     developers of Varnish Cache gather to share experiences and plan
     future development.
 
+VUT
+    Varnish UTilities -- An API for client utilities to tap into VSM or VSC.
+
 VWx
     Varnish Waiter 'x' -- A code module to monitor idle sessions.