Cleanup `primitive-extras` (#5210), test `dhall-yaml` (#5212)
Cleanup `primitive-extras` (#5210), test `dhall-yaml` (#5212)

Daniel-Diaz/stackage,jonschoning/stackage,fpco/stackage,mrkkrp/stackage,iand675/stackage,massysett/stackage,clinty/stackage,soenkehahn/stackage,michalkonecny/stackage,simonmichael/stackage