bump the library version to 3.5.1 and update the release log

Author: stephengold

gradle.properties

@@ -1,7 +1,7 @@
 ## configure Gradle properties for building the Jolt-JNI Project
 
 # Jolt-JNI version string:
-jjVersion = 3.5.1-SNAPSHOT
+jjVersion = 3.5.1
 
 ## default artifact ID (used when -Partifact= isn't specified on the command line)
 artifact = jolt-jni

release-log.md

@@ -1,5 +1,15 @@
 # Release log for the Jolt-JNI project
 
+## Version 3.5.1 released on TBD
+
++ Bugfixes:
+  + race condition in `JoltPhysicsObject.startCleaner()`
+  + `Jolt.listClasses()` depends on the local charset
++ Altered the half-extent constraints for `BoxShape` and `BoxShapeSettings`.
++ Updated the Jolt-Physics source and assets to v5.5.0 (=23dadd0e).
++ Updated the OSHI library to v6.9.2 .
+
+
 ## Version 3.5.0 released on 28 October 2025
 
 + Bugfixes: