doc PG 18 relnotes: set release date, remove "CURRENT AS OF"

bmomjian · bmomjian · commit 144de0341bde · 2025-09-18T11:29:36.000-04:00
Backpatch-through: 18 only
diff --git a/doc/src/sgml/release-18.sgml b/doc/src/sgml/release-18.sgml
@@ -6,7 +6,7 @@
 
   <formalpara>
    <title>Release date:</title>
-   <para>2025-??-??, CURRENT AS OF 2025-08-29</para>
+   <para>2025-09-25</para>
   </formalpara>
 
   <sect2 id="release-18-highlights">
