Upstream has released updates that appears to apply and compile correctly.
This update has not been tested by PaperMC and as with ANY update, please do your own testing
BungeeCord Changes:
830ee8f2 #3061: Continue to fallback to underlying URLClassLoader
425dd451 Override classloader close method for completeness
6a039de8 Add preview of automatic library support
Upstream updated to Netty 4.1.53.Final
Update maven-shade-plugin.log4j2-cachefile-transformer to 2.13.2 for compatibility with maven-shade-plugin 3.2.3
This patch was heavily intented to fix a server side issue which
is generally no longer relevant, not to mention the cost of interning
only cements this patch into it's grave