Fix CI build in v1.7

[schillic]

ERROR: Unsatisfiable requirements detected for package JuMP [4076af6c]:
 JuMP [4076af6c] log:
 ├─possible versions are: 0.18.3-0.23.0 or uninstalled
 ├─restricted to versions 0.22 by an explicit requirement, leaving only versions 0.22.0-0.22.3
 └─restricted by compatibility requirements with CDDLib [3391f64e] to versions: 0.21.0-0.21.10 — no versions left
   └─CDDLib [3391f64e] log:
     ├─possible versions are: 0.4.0-0.9.0 or uninstalled
     └─restricted to versions 0.7 by an explicit requirement, leaving only versions 0.7.0

Originally posted by @schillic in #605 (comment)

[schillic]

This seems to work now. Strange...