chore(deps): update dependency org.assertj:assertj-core to v3.21.0

Author: renovate-bot

pom.xml

@@ -50,7 +50,7 @@
         <jacoco-maven-plugin.version>0.8.6</jacoco-maven-plugin.version>
         <maven-source-plugin.version>3.2.1</maven-source-plugin.version>
         <jacoco-maven-plugin.version>0.8.7</jacoco-maven-plugin.version>
-        <assertj.version>3.20.2</assertj.version>
+        <assertj.version>3.21.0</assertj.version>
         <commons-io.version>2.11.0</commons-io.version>
         <spring-cloud.version>Greenwich.RELEASE</spring-cloud.version>
         <wiremock.version>2.27.2</wiremock.version>