CompatHelper: bump compat for ObjectFile to 0.4, (keep existing compat)

[github-actions]

This pull request changes the compat entry for the ObjectFile package from 0.3.6 to 0.3.6, 0.4.
This keeps the compat entries for earlier versions.

Note: I have not tested your package with this new compat entry.
It is your responsibility to make sure that your package tests pass before you merge this pull request.

[eschnett]

The function readmeta in ObjectFile now returns a one-element vector instead of a scalar. (Except for fat MachO binaries, these are still returned as scalars and they are iterable.)

I think the solution is to loop over the return values of readmeta. Or we can use only as stop-gap measure.

[eschnett]

@giordano What do you think about adding loops as I suggest above?

[giordano]

I think that sounds good, and readmeta returning a vector instead instead of a single object matches my recollection of the problem.