Using Maven surefire plugin >= 2.20 breaks tests

[ralphlange]

Updating the Maven surefire plugin to a version >= 2.20 breaks tests on all Java versions.
See e.g. https://github.com/ralphlange/jca/runs/7424300112?check_suite_focus=true

It's always in the connection tests, where timeouts occur.
Something connected to multithreading or timing has changed. Probably the tests need to be updated to work with newer plugin versions. Simply extending the timeout (pend_io) periods does not help.

When that is done, JCA is probably fit for Java 16.

Error:  Tests run: 1, Failures: 0, Errors: 1, Skipped: 0, Time elapsed: 5.015 s <<< FAILURE! - in com.cosylab.epics.caj.impl.handlers.test.AllTests
Error:  testExceptionResponse(com.cosylab.epics.caj.impl.handlers.test.ExceptionResponseIT)  Time elapsed: 5.01 s  <<< ERROR!
gov.aps.jca.TimeoutException: pendIO timed out
	at com.cosylab.epics.caj.impl.handlers.test.ExceptionResponseIT.setUp(ExceptionResponseIT.java:86)
[INFO] Running com.cosylab.epics.caj.impl.test.AllTests
Channel Access Server in Java v1.1.D1
CLASS   : com.cosylab.epics.caj.cas.CAJServerContext
VERSION : Channel Access Server in Java [Java] v1.1.D1
SERVER : com.cosylab.epics.caj.cas.util.DefaultServerImpl
BEACON_ADDR_LIST : 
AUTO_BEACON_ADDR_LIST : true
BEACON_PERIOD : 15.0
BEACON_PORT : 5065
TCP SERVER_PORT : 5064
UDP SERVER_PORT : 5064
MAX_ARRAY_BYTES : 16384
IGNORE_ADDR_LIST: 
STATE : INITIALIZED
Error:  Tests run: 5, Failures: 1, Errors: 0, Skipped: 0, Time elapsed: 10.097 s <<< FAILURE! - in com.cosylab.epics.caj.impl.test.AllTests
Error:  testExtenderHeaderSupport(com.cosylab.epics.caj.impl.test.CATransportExtendedHeaderIT)  Time elapsed: 3.014 s  <<< FAILURE!
java.lang.AssertionError: expected:<gov.aps.jca.CAStatus[NORMAL=0,SUCCESS=1]=Normal successful completion> but was:<null>
	at com.cosylab.epics.caj.impl.test.CATransportExtendedHeaderIT.doGet(CATransportExtendedHeaderIT.java:86)
	at com.cosylab.epics.caj.impl.test.CATransportExtendedHeaderIT.testExtenderHeaderSupport(CATransportExtendedHeaderIT.java:103)