Merge branch 'ralf/drop-8.7' into 'master'

drop support for Coq 8.7

See merge request !170
5 jobs for master in 12 minutes and 54 seconds
Status Job ID Name Coverage
  Build
passed #76911
fp
build-coq.8.10.2

00:06:10

passed #76910
fp-timing
build-coq.8.11.2

00:04:00

passed #76909
fp
build-coq.8.12.dev

00:12:38

passed #76913
fp
build-coq.8.8.2

00:03:39

passed #76912
fp
build-coq.8.9.1

00:04:18