Bump some Maven plugins

junit 4.13.1 -> 4.13.2 (minor update)

maven javadoc 3.2.0 -> 3.3.2 (bugfixes, e.g. support javadoc generation with modular JDKs)

mockito 3.7.7 -> 3.12.4 (bugfixes to support newer JDKs, e.g. 17)

tycho 2.5.0 -> 2.7.1 (bugfixes, prepare JDK17 support)

jetty maven plugin 9.4.43.v20210629 -> 9.4.46.v20220331 (minor updates, only used for p2 server during build)

p2-maven-plugin 1.5.0 -> 2.0.0 (prepare JDK 17 support)

build-helper-maven-plugin 3.2.0 -> 3.3.0 (minor update)