pgpainless: fails to build from source with Java 21 due to SecurityManager UnsupportedException

[Vladimir Petko]

The package fails to build from source due to the exception during tests:

   JUnit
Jupiter:SignUsingPublicKeyBehaviorTest:testSignatureCreationAndVerification()
     MethodSource [className =
'org.pgpainless.cli.misc.SignUsingPublicKeyBehaviorTest', methodName =
'testSignatureCreationAndVerification', methodParameterTypes = '']
     => java.lang.UnsupportedOperationException: The Security Manager is
deprecated and will be removed in a future release
        java.base/java.lang.System.setSecurityManager(System.java:430)
com.ginsberg.junit.exit.SystemExitExtension.beforeEach(SystemExitExtension.java:95)
        java.base/java.util.ArrayList.forEach(ArrayList.java:1596)
        java.base/java.util.ArrayList.forEach(ArrayList.java:1596)
        Suppressed: org.opentest4j.AssertionFailedError: Expected
System.exit(79) to be called, but it was not. ==> expected: <79> but was:
<null>
com.ginsberg.junit.exit.SystemExitExtension.afterEach(SystemExitExtension.java:67)
          [...]

The tests need to run with -Djava.security.manager=allow for the junit
SystemExit extension to work.

[Vladimir Petko (vpa1977)]

Fixed in Debian 1.6.6-2 and synced. Restarted autopkgtest.