avoid depending on heavily invalidating pacakges

[KristofferC]

These are not used in the package and should hence not be depended on. Adding heavily invalidating packages as dependencies kind of just "kicks the can down the road" and causes DataFrames to be unattractive to depend on.

Tagging some people who were active in #3285: @bkamins, @timholy, @quinnj, @nalimilan

[bkamins]

I am OK to proceed as @KristofferC proposes, but before moving forward a comment from other involved contributors is welcome.

[nalimilan]

Would there be a way to store precompiled code for the extension so that no recompilation is needed after loading InlineStrings and SentinelArrays? For example, if we called include("src/precompile.jl") from the extension, would it store new versions of methods that are invalidated when loading it?

[quinnj]

I echo @bkamins's question from the original issue/PR: should we instead focus on fixing the invalidations in these upstream packages? I'm happy to help push on that; I just wasn't aware of the issue or what is being measured exactly in calling them heavily invalidating packages.