Update CHANGELOG and docs for v8.31.0

Author: gaeljw

CHANGELOG.md

@@ -19,6 +19,8 @@ See also the [CHANGELOG](https://github.com/cucumber/cucumber-jvm/blob/master/CH
 
 ### Fixed
 
+## [8.31.0] (2025-07-28)
+
 ## [8.30.2-SNAPSHOT] (2025-07-28)
 
 ### Changed
@@ -752,6 +754,7 @@ _Although there is no visible change from a user perspective, there are signific
 
 <!-- Releases -->
 [Unreleased]: https://github.com/cucumber/cucumber-jvm-scala/compare/v8.30.2-SNAPSHOT...HEAD
+[8.31.0-SNAPSHOT]:  https://github.com/cucumber/cucumber-jvm-scala/compare/v8.30.2...v8.31.0-SNAPSHOT
 [8.30.2-SNAPSHOT]:  https://github.com/cucumber/cucumber-jvm-scala/compare/v8.30.1...v8.30.2-SNAPSHOT
 [8.30.1]:  https://github.com/cucumber/cucumber-jvm-scala/compare/v8.30.0...v8.30.1
 [8.30.0]:  https://github.com/cucumber/cucumber-jvm-scala/compare/v8.29.0...v8.30.0

version.sbt

@@ -1 +1 @@
-ThisBuild / version := "8.30.2-SNAPSHOT"
+ThisBuild / version := "8.31.0"