enable proof-length checking during CI

6 jobs for master in 3 minutes and 31 seconds (queued for 1 second)
latest
Status Job ID Name Coverage
  Build
passed #36611
1.8.0-coq-8.8

00:02:02

passed #36613
1.9.0-coq-8.9

00:02:04

failed #36612
allowed to fail
1.9.0-coq-dev

00:00:18

 
  Process
passed #36615
doc

00:00:25

passed #36616
proof-length

00:00:17

passed #36614
validate

00:01:27

 
Name Stage Failure
failed
1.9.0-coq-dev Build There is an unknown failure, please try again
File "./util/seqset.v", line 19, characters 42-52:
Error: The reference mkPredType was not found in the current environment.

Makefile:658: recipe for target 'util/seqset.vo' failed
make[1]: *** [util/seqset.vo] Error 1
make[1]: *** Waiting for unfinished jobs....
make: *** [all] Error 2
Makefile:320: recipe for target 'all' failed
ERROR: Job failed: exit code 1