Update CI images to 8.6.* and cabal-2.4.*
The docker images need updating to a more recent GHC release. Probably best to do this after 8.6.4 is released.
Trac metadata
| Trac field | Value |
|---|---|
| Version | 8.6.3 |
| Type | Task |
| TypeOfFailure | OtherFailure |
| Priority | normal |
| Resolution | Unresolved |
| Component | Compiler |
| Test case | |
| Differential revisions | |
| BlockedBy | |
| Related | |
| Blocking | |
| CC | |
| Operating system | |
| Architecture |