Remove `ghostscript` dependency

[mjbommar]

Is your feature request related to a problem? Please describe. It appears that all gs usage was removed in 2020. However, ghostscript is still installed, e.g., in Dockerfile. This results in AGPL-licensed software being distributed - though hopefully not used - with the application.

Describe the solution you'd like Remove all ghostscript dependencies.

Describe alternatives you've considered Relicense the project as AGPL, which you appear to have purposefully avoided.

[slbayer]

Random stranger here: the current version of camelot uses ghostscript, and the table detection script in master still uses camelot.