RelNotes: fix typo in release notes for 2.52.0

Introduced via aea86cf (The nineteenth batch, 2025-10-14).

Signed-off-by: Taylor Blau <me@ttaylorr.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Author: ttaylorr

Documentation/RelNotes/2.52.0.adoc

@@ -53,7 +53,7 @@ UI, Workflows & Features
 
  * Configuration variables that take a pathname as a value
    (e.g. blame.ignorerevsfile) can be marked as optional by prefixing
-   ":(optoinal)" before its value.
+   ":(optional)" before its value.
 
  * Show 'P'ipe command in "git add -p".