The following artifacts contain references to JUnit4:
codec/yang-data-codec-binfmt codec/yang-data-codec-gson codec/yang-data-codec-xml common/util data/yang-data-impl data/yang-data-tree-ri data/yang-data-tree-spi parser/odlext-parser-support parser/rfc6241-parser-support parser/rfc6536-parser-support parser/rfc6643-parser-support parser/rfc7952-parser-support parser/rfc8040-parser-support parser/rfc8528-parser-support parser/rfc8639-parser-support parser/yang-parser-impl parser/yang-parser-spi plugin/yang-maven-plugin-it yang/yang-repo-spi
Migrate them to JUnit5. This includes cleaning up things like assertThat(instanceOf()), assertTrue(foo instanceof x) to use assertInstanceOf(), etc.