fix and reject warnings on Coq 8.13

5 jobs for ci/ralf/warnings in 10 minutes and 7 seconds (queued for 3 seconds)
Status Job ID Name Coverage
  Build
passed #110351
fp
build-coq.8.10.2

00:05:29

passed #110350
fp
build-coq.8.11.2

00:05:11

passed #110349
fp-timing
build-coq.8.12.2

00:04:10

passed #110348
fp
build-coq.8.13.0

00:04:55

passed #110347
fp
build-coq.dev

00:10:06