Fix v4 changelog latest date (#2333)

Author: matt-aitken

docs/upgrade-to-v4.mdx

@@ -1184,7 +1184,7 @@ We recommend enabling this option and testing in a staging or preview environmen
 
 </Update>
 
-<Update label="July 24, 2025" description="v4.0.0-beta.26">
+<Update label="August 1, 2025" description="v4.0.0-beta.26">
   [Release
   v4.0.0-beta.26](https://github.com/triggerdotdev/trigger.dev/releases/tag/trigger.dev%404.0.0-v4-beta.26).