internal/cueversion: bump LanguageVersion for v0.10
Work in master has begun for v0.10, so bump the language version
following the instructions at:
https://github.com/cue-lang/cue/wiki/Notes-for-project-maintainers#doing-a-release
Signed-off-by: Daniel Martí <mvdan@mvdan.cc>
Change-Id: I336cd44de6291dafa5e96ee9c4f214c3f5f192f0
Reviewed-on: https://review.gerrithub.io/c/cue-lang/cue/+/1196303
Reviewed-by: Roger Peppe <rogpeppe@gmail.com>
TryBot-Result: CUEcueckoo <cueckoo@cuelang.org>
Unity-Result: CUE porcuepine <cue.porcuepine@gmail.com>