ci: bump minimal rocq version and improve ci #3939

Job	Run time
quick-build (9.1, ubuntu-latest)	3m 22s
opam-build (9.1, ubuntu-latest)	4m 26s
quick-build (9.0, ubuntu-latest)	3m 35s
nix	2m 10s
build (dev, --warnings)	3m 32s
opam-build (9.0, ubuntu-latest)	4m 13s
opam-build (dev, ubuntu-latest)	4m 14s
build (9.0)	3m 37s
build (9.1)	3m 35s
quick-build (dev, ubuntu-latest)	3m 20s
doc-alectryon	8m 23s
doc-dep-graphs	8m 24s
install (9.1)	1m 51s
doc-timing	3m 42s
install (9.0)	1m 52s
doc-coqdoc	3m 31s
coqchk (dev)	2m 3s
coqchk (9.1)	5m 37s
install (dev)	1m 53s
coqchk (9.0)	5m 33s
delete-artifacts	8s
deploy-doc	1s
	1h 19m 2s

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