Fix Java 21 tests by placing mockito before assertj

https://groups.google.com/g/byte-buddy/c/H3auRC-SRts/m/7NCRN2wAAwAJ
notes that the version of bytebuddy in assertj does not support Java 21
while the version of bytebuddy in mockito supports Java 21.  Load mockito
first so that the newer version of bytebuddy is used for the tests.

This change is necessary but not sufficient to pass the tests on Java 21.
The tests run much better on Java 21 with this change, but there are still
two tests that fail.  They will need to be investigated and resolved in
a separate pull request.

pom.xml

@@ -140,6 +140,16 @@
       <artifactId>pipeline-rest-api</artifactId>
     </dependency>
 
+    <!-- mockito must precede assertj until assertj supports Java 21 -->
+    <!-- mockito provides a Java 21 capable version of bytebuddy -->
+    <!-- TODO: restore ordering once assertj supports Java 21 -->
+    <dependency>
+      <groupId>org.mockito</groupId>
+      <artifactId>mockito-core</artifactId>
+      <scope>test</scope>
+    </dependency>
+    <!-- assertj must follow mockito until assertj supports Java 21 -->
+    <!-- assertj does not provide a Java 21 capable version of bytebuddy -->
     <dependency>
       <groupId>org.assertj</groupId>
       <artifactId>assertj-core</artifactId>
@@ -152,18 +162,6 @@
       <version>${JUnitParams.version}</version>
       <scope>test</scope>
     </dependency>
-    <dependency>
-      <groupId>org.mockito</groupId>
-      <artifactId>mockito-core</artifactId>
-      <version>${mockito.version}</version>
-      <scope>test</scope>
-    </dependency>
-<!--    <dependency>-->
-<!--      <groupId>org.mockito</groupId>-->
-<!--      <artifactId>mockito-inline</artifactId>-->
-<!--      <version>${mockito.version}</version>-->
-<!--      <scope>test</scope>-->
-<!--    </dependency>-->
     <dependency>
       <groupId>com.github.stefanbirkner</groupId>
       <artifactId>system-lambda</artifactId>