internal/pkg: remove unnecessary runtime fields
These have been present since 2022, but were never actually used.
Signed-off-by: Daniel Martí <mvdan@mvdan.cc>
Change-Id: I8bb50674840196db3084eb0cb72fe5316fba6122
Reviewed-on: https://review.gerrithub.io/c/cue-lang/cue/+/1234438
Reviewed-by: Marcel van Lohuizen <mpvl@gmail.com>
Unity-Result: CUE porcuepine <cue.porcuepine@gmail.com>
TryBot-Result: CUEcueckoo <cueckoo@cuelang.org>