fix: Mockito inline mocking for Java 21+ (#207)

Before this fix the execution of the maven surefire
plugin with Java 21 logged warnings that mockito should be added as
a java agent, because the self-attaching won't be supported in future
java releases.
In Java 24 the test just broke.

This problem is solved by modifying the pom.xml of the parent and doing
this changes:

* Adding mockito as a java agent.
* Removing the surefireArgLine from the properties. This can be
added back when it's needed (for example when JaCoCo will be used).

Furthermore, the pom.xml in the mcp-spring-* modules now have
the byte-buddy dependency included, as the test would otherwise break
when trying to mock McpSchema#CreateMessageRequest.

Fixes #187

Co-authored-by: Dariusz Jędrzejczyk <dariusz.jedrzejczyk@broadcom.com>

mcp-spring/mcp-spring-webflux/pom.xml

@@ -82,6 +82,12 @@
 			<version>${mockito.version}</version>
 			<scope>test</scope>
 		</dependency>
+		<dependency>
+			<groupId>net.bytebuddy</groupId>
+			<artifactId>byte-buddy</artifactId>
+			<version>${byte-buddy.version}</version>
+			<scope>test</scope>
+		</dependency>
 		<dependency>
 			<groupId>io.projectreactor</groupId>
 			<artifactId>reactor-test</artifactId>

mcp-spring/mcp-spring-webmvc/pom.xml

@@ -77,6 +77,12 @@
 			<version>${mockito.version}</version>
 			<scope>test</scope>
 		</dependency>
+		<dependency>
+			<groupId>net.bytebuddy</groupId>
+			<artifactId>byte-buddy</artifactId>
+			<version>${byte-buddy.version}</version>
+			<scope>test</scope>
+		</dependency>
 		<dependency>
 			<groupId>org.testcontainers</groupId>
 			<artifactId>junit-jupiter</artifactId>

pom.xml

@@ -57,6 +57,7 @@
 		<java.version>17</java.version>
 		<maven.compiler.source>17</maven.compiler.source>
 		<maven.compiler.target>17</maven.compiler.target>
+		<surefireArgLine/>
 
 		<assert4j.version>3.26.3</assert4j.version>
 		<junit.version>5.10.2</junit.version>
@@ -163,13 +164,23 @@
 					</execution>
 				</executions>
 			</plugin>
+			<plugin>
+				<groupId>org.apache.maven.plugins</groupId>
+				<artifactId>maven-dependency-plugin</artifactId>
+				<executions>
+					<execution>
+						<goals>
+							<goal>properties</goal>
+						</goals>
+					</execution>
+				</executions>
+			</plugin>
 			<plugin>
 				<groupId>org.apache.maven.plugins</groupId>
 				<artifactId>maven-surefire-plugin</artifactId>
 				<version>${maven-surefire-plugin.version}</version>
 				<configuration>
-					<argLine>${surefireArgLine}</argLine>
-
+					<argLine>${surefireArgLine} -javaagent:${org.mockito:mockito-core:jar}</argLine>
 					<useFile>false</useFile>
 					<trimStackTrace>false</trimStackTrace>