Bump json from 20201115 to 20210307 in /examples (#3884)

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)

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examples/linked-container/build.gradle

@@ -8,7 +8,7 @@ repositories {
 dependencies {
     compileOnly 'org.slf4j:slf4j-api:1.7.30'
     implementation 'com.squareup.okhttp3:okhttp:4.9.0'
-    implementation 'org.json:json:20201115'
+    implementation 'org.json:json:20210307'
     testImplementation 'org.postgresql:postgresql:42.2.18'
     testImplementation 'ch.qos.logback:logback-classic:1.2.3'
     testImplementation 'org.testcontainers:postgresql'