Add CI for GHCJS

[harendra-kumar]

GHCJS-8.4 build failed here: https://app.circleci.com/pipelines/github/composewell/streamly/1398/workflows/c3b2c7b0-8af4-4000-948f-8126db769927/jobs/5089 when fusion-plugin was added to the cabal file.

[pranaysashank]

Last I checked there was no way to depend on ghc library when using ghcjs.