Removal of Input File Workflow

[maxdinkel]

We recently merged PR #187, which removed the legacy input-file-based workflow from QUEENS.

After evaluating both the input-file-based and script-based workflows, we believe that the script-based approach offers substantial advantages and has become the preferred method for most users.
Given that the input-file-based workflow is no longer actively used by most users, we’ve decided to retire it in order to reduce maintenance overhead.