Embeds arrival_uniq into arrival sequences

This avoid having to state arrival_uniq again and again almost each
time an arrival sequence is used, since arrival sequence without
uniq_arrival aren't really a thing.
15 jobs for !185 with embed_arr_seq_uniq in 9 minutes and 24 seconds (queued for 1 minute and 30 seconds)
latest merge request
Name Stage Failure
failed
coq-dev Build
# It cannot be used in a binder.
#
# make[1]: *** [Makefile:816: util/unit_growth.vo] Error 1
# make[1]: *** Waiting for unfinished jobs....
# make: *** [Makefile:415: all] Error 2

'opam install -y -v -j 2 coq-prosa' failed.
Cleaning up file based variables
ERROR: Job failed: exit code 1
failed
spell-check Build
Removing without-proofs/

Skipping Git submodules setup
Executing "step_script" stage of the job script
Using docker image sha256:f38333aa26aa2d36b20ad655bae19488d2e9a2498f1f2c20490ba217ee0e651e for bbbrandenburg/aspell-ci with digest bbbrandenburg/aspell-ci@sha256:0de5540340ad623f9c4a394a025d2be71d1de878fe1a527fe7a5268dc44cff4d ...
$ scripts/flag-typos-in-comments.sh `find . -iname '*.v' ! -path './classic/*'`
./behavior/arrival_sequence.v: potentially misspelled word 'JobArrival'
Cleaning up file based variables
ERROR: Job failed: exit code 1