fix build for Coq 8.10

8 jobs for master in 8 minutes and 37 seconds (queued for 1 second)
Status Job ID Name Coverage
  Build
passed #36917
fp
build-coq.8.10.dev

00:07:51

passed #36923
fp
build-coq.8.7.2

00:02:53

passed #36922
fp-timing
build-coq.8.8.0

00:02:44

passed #36921
fp
build-coq.8.8.1

00:02:58

passed #36920
fp
build-coq.8.8.2

00:03:08

passed #36919
fp-timing
build-coq.8.9.0

00:03:24

passed #36918
fp
build-coq.8.9.1

00:03:39

passed #36916
fp
build-coq.dev

00:08:35