gdb debugging Quarkus apps without setting the sources directory no longer works as of GraalVM/Mandrel 21.1

[zakkak]

Please see quarkusio/quarkus#20321 for more details.

Upstream fix: oracle#3828

[zakkak]

Marking this as won't fix, please see oracle#3828 for more details and quarkusio/quarkus#20355 for the Quarkus patch to resolve the issue there.