Bump json from 20201115 to 20210307

Bumps [json](https://github.com/douglascrockford/JSON-java) from 20201115 to 20210307.
- [Release notes](https://github.com/douglascrockford/JSON-java/releases)
- [Commits](https://github.com/douglascrockford/JSON-java/commits)

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

build.gradle

@@ -56,7 +56,7 @@ dependencies {
     implementation "org.openjfx:javafx-graphics:15.0.1:$fxPlatform"
     implementation "org.openjfx:javafx-fxml:15.0.1:$fxPlatform"
 
-    implementation group: 'org.json', name: 'json', version: '20201115'
+    implementation group: 'org.json', name: 'json', version: '20210307'
     implementation 'de.jangassen:nsmenufx:3.1.0'
 //    implementation 'net.java.dev.jna:jna:jpms:5.7.0'