Remove invalid "test" attribute. am: d78a4dc913 am: 11541a49a8

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/linkme-impl/+/2780512

Change-Id: I9cef78fbe51824f31919a90ed7d6b2867c0f5df0
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>