Misc cleanups to Overture, Colimits/Quotient #2883

Job	Run time
quick-build (supported, ubuntu-latest)	3m 10s
build (supported)	3m 20s
quick-build (latest, ubuntu-latest)	3m 11s
build (latest)	3m 24s
nix	2m 7s
build (dev, --warnings)	3m 19s
quick-build (dev, ubuntu-latest)	3m 8s
opam-build (supported, ubuntu-latest)	4m 53s
opam-build (latest, ubuntu-latest)	4m 25s
opam-build (dev, ubuntu-latest)	4m 29s
doc-timing	1m 29s
doc-alectryon	14m 50s
doc-coqdoc	1m 28s
coqchk (supported)	1m 58s
doc-dep-graphs	7m 31s
coqchk (latest)	1m 53s
install (supported)	1m 40s
coqchk (dev)	1m 50s
install (latest)	1m 38s
install (dev)	1m 42s
deploy-doc	0s
delete-artifacts	5s
	1h 11m 30s

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