v0.3.13

Trixi2Vtk v0.3.13

Diff since v0.3.12

Merged pull requests:

• Prepare test setup for CI tests triggered from upstream (#79) (@sloede)
• CompatHelper: bump compat for ReadVTK to 0.2 for package test, (keep existing compat) (#80) (@github-actions[bot])
• allow Trixi.jl v0.6 for tests (#81) (@ranocha)
• coverallsapp at v2 (#83) (@ranocha)
• coverallsapp at v2 (again) (#84) (@JoshuaLampert)
• Bump actions/upload-artifact from 3 to 4 (#85) (@dependabot[bot])