rules_jvm_external CI broken with Bazel@HEAD

Example Breakage: https://buildkite.com/bazel/bazel-at-head-plus-downstream/builds/2091#cc1c6c37-86c8-443e-b73e-a1b21bcd3734

Culprit finder points to https://github.com/bazelbuild/bazel/commit/80feea06cbf06486280dac065e3caec5facbedb9 but this looks like a rollback of a rollback of a rollback of a rollback....

Start with the linked Buildkite Bazel-at-head-plus-downstream failure and inspect Bazel commit 80feea06cbf06486280dac065e3caec5facbedb9. Reproduce the rules_jvm_external CI breakage against Bazel@HEAD, then identify the compatibility change needed and verify that the downstream build passes.

Written by the indexing model from the issue text.