Since version 2.15.0 `log4j-jul` contains a `Log4jBridgeHandler`,
that forwards JUL to Log4j 2.x and synchronizes the logger levels of
the two frameworks.
This commmit adds support for the `Log4jBridgeHandler` and sets it as
the bridge handler for the Log4j 2.x stack, replacing the existing
JUL to SLF4J bridge that was used previously.
See gh-30003
728e27d193