update the Heart library to v9.3.0

Author: stephengold

gradle/libs.versions.toml

@@ -7,7 +7,7 @@ jme = "3.9.0-stable"
 [libraries]
 
 groovy-jsr223 = "org.apache.groovy:groovy-jsr223:5.0.3"
-heart = "com.github.stephengold:Heart:9.2.0"
+heart = "com.github.stephengold:Heart:9.3.0"
 
 jme3-awt-dialogs = { module = "org.jmonkeyengine:jme3-awt-dialogs", version.ref = "jme" }
 jme3-core = { module = "org.jmonkeyengine:jme3-core", version.ref = "jme" }