refactor(3p/lisp/mime4cl): use trivial-gray-streams r/3676

This should be a net positive for portability and lets us drop some of
the CMUCL cruft (which we don't test anyway, CMU support may have
regressed regardless).

Change-Id: I85664d82d211177da1db9eebea65c956295b09f7
Reviewed-on: https://cl.tvl.fyi/c/depot/+/5067
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>

0 files changed, 0 insertions, 0 deletions