CompatHelper: bump compat for Interpolations to 0.16, (keep existing compat)

[github-actions]

This pull request changes the compat entry for the Interpolations package from 0.13.4 to 0.13.4, 0.16.
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.

[icweaver]

Is it ok to merge this? Seems to currently be conflicting with Photometry.jl since its recent compat bump with JuliaMath/Interpolations.jl:

Photometry.jl: Error During Test at /home/runner/work/JuliaAstro.github.io/JuliaAstro.github.io/test/runtests.jl:41
  Test threw exception
  Expression: Pkg.add(url = package.repo) == nothing
  Unsatisfiable requirements detected for package Interpolations [a98d9a8b]:
   Interpolations [a98d9a8b] log:
   ├─possible versions are: 0.3.6 - 0.16.1 or uninstalled
   ├─restricted to versions 0.14.2 - 0.16 by Photometry [af68cb61], leaving only versions: 0.14.2 - 0.16.1
   │ └─Photometry [af68cb61] log:
   │   ├─possible versions are: 0.9.4 or uninstalled
   │   ├─restricted to versions * by project [dd8e088e], leaving only versions: 0.9.4
   │   │ └─project [dd8e088e] log:
   │   │   ├─possible versions are: 0.0.0 or uninstalled
   │   │   └─project [dd8e088e] is fixed to version 0.0.0
   │   └─Photometry [af68cb61] is fixed to version 0.9.4
   └─restricted to versions 0.13.4 - 0.13 by AstroLib [c7932e45] — no versions left
     └─AstroLib [c7932e45] log:
       ├─possible versions are: 0.4.4 or uninstalled
       ├─restricted to versions * by project [dd8e088e], leaving only versions: 0.4.4
       │ └─project [dd8e088e] log: see above
       └─AstroLib [c7932e45] is fixed to version 0.4.4

[cgarling]

LGTM