migrate to junit5 (#5572)

Signed-off-by: Sally MacFarlane <macfarla.github@gmail.com>

datatypes/build.gradle

@@ -37,7 +37,6 @@ dependencies {
   implementation 'io.tmio:tuweni-bytes'
   implementation 'io.tmio:tuweni-units'
 
-  testImplementation 'junit:junit'
   testImplementation 'org.assertj:assertj-core'
   testImplementation 'org.junit.jupiter:junit-jupiter'
   testRuntimeOnly 'org.junit.jupiter:junit-jupiter-engine'

datatypes/src/test/java/org/hyperledger/besu/datatypes/HashTest.java

@@ -16,7 +16,7 @@ package org.hyperledger.besu.datatypes;
 
 import static org.assertj.core.api.Assertions.assertThat;
 
-import org.junit.Test;
+import org.junit.jupiter.api.Test;
 
 public class HashTest {
 

datatypes/src/test/java/org/hyperledger/besu/datatypes/WeiTest.java

@@ -19,7 +19,7 @@ import static org.assertj.core.api.Assertions.assertThat;
 import java.math.BigInteger;
 import java.util.Arrays;
 
-import org.junit.Test;
+import org.junit.jupiter.api.Test;
 
 public class WeiTest {