remove hard coded surefire config (#199)

the hard coded surefire config means it can not be overridden in CI or the CLI.

Whilst forkCount is the most pressing - if unlimited threads really are used, that would seem like an issue for people on slow computers, or VMs with not a lot of CPU.

pom.xml

@@ -44,15 +44,6 @@
             <compatibleSinceVersion>1.44</compatibleSinceVersion>
           </configuration>
         </plugin>
-      <plugin>
-        <groupId>org.apache.maven.plugins</groupId>
-        <artifactId>maven-surefire-plugin</artifactId>
-        <configuration>
-          <forkCount>1C</forkCount>
-          <parallel>all</parallel>
-          <useUnlimitedThreads>true</useUnlimitedThreads>
-        </configuration>
-      </plugin>
       </plugins>
     </build>