I dont know if we are publishing the uber jars to Maven Central anymore (My personal rationale behind why it might have stopped is perhaps because Maven Central is meant to house artifacts which will be consumed as dependencies and I dont think anyone consumes the uber jar as a maven dependency and so its no longer being published).
Maybe you could request your IT team to add the github releases page for selenium also into the whitelisting list?
The only other alternative that I can think of is for you to build and release the Selenium uber jar into your Maven Repository ( not a scalable one to be honest)