T12903 unexpectedly times out
See https://gitlab.haskell.org/ghc/ghc/-/jobs/968679:
Timeout happened...killed process "cd "rts/T12903.run" && ./T12903 "...
Wrong exit code for T12903(normal)(expected 0 , actual 99 )
*** unexpected failure for T12903(normal)Note that this test is already marked fragile or skipped on some platforms and ways: