Decide on how to ship reproducible Julia code at release

[seabbs]

In #32 (and #36) we remove the Manifest.toml from EpiAware as this was not required for between contributor reproducibility and was causing merge issues in a PR workflow.

Potentially shipping this at a release point (or an overarching Manifest.toml) would be a good idea for ensuring the reproducibility of this analysis (not the EpiAware.jl package. We could also potentially do this in other ways (such as shipping a Docker image).

This issue is for discussing and deciding on the right course for this and also deciding when we should aim to do this.

[SamuelBrand1]

At this time, I think we have moved towards EpiAware as a package which the pipeline uses (plus with an aspiration to an EpiAwarePipeline package).

The specific analysis done in the pipeline should ship with a Manifest.toml, but the other package(s) shouldn't (as per usual package management in Julia).