fix too many open images warning

[djdameln]

Description

This PR fixes a bug that caused too many matplotlib figures to be retained in memory. visualizer.generate() was unintentionally called twice for every image, causing the number of open images to build up as the test loop progressed. Fixed by leaving the responsibility of calling visualizer.generate() to the callback class instead of the visualizer itself.

Note: Since this bug affected development, I target development in this PR. Will rebase the feature branch to pull in the changes there.

Changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

Checklist

• My code follows the pre-commit style and check guidelines of this project.
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing tests pass locally with my changes

[ashwinvaidya17]

Thanks for looking into this