Case of `include(joinpath(...))` with explicit strings

[theogf]

RIght now all include of type

include(joinpath("subdir", "myfile.jl"))

are ignored by the linter. Although it's apparently not best practice it would be great for the linter to be able to treat them as include("subdir/myfile.jl").

[davidanthoff]

We could offer a code action to remove the unnecessary joinpath :)

[pfitzseb]

Our code already tries to handle this case, but it's obviously buggy.