Call Pkg.upgrade_manifest() when updating packages

[fonsp]

A bit annoying that Pkg.upgrade_manifest() throws an error when the manifest is already up to date... so i just put it in an empty try catch

untested

[github-actions]

Try this Pull Request!

Open Julia and type:

julia> import Pkg
julia> Pkg.activate(temp=true)
julia> Pkg.add(url="https://github.com/fonsp/Pluto.jl", rev="fonsp-patch-3")
julia> using Pluto