Minor cleanups

[joeshannon]

• Delete git_merge.png This looks like a left over artifact from the skeleton project.
• Remove reference to plot_spec.png This likely leaked in from the scanspec project.

[joeshannon]

I'm not really sure why the tests are failing, seemed to work locally.

[GDYendell]

The type of error has changed?

https://github.com/DiamondLightSource/python-copier-template/blob/main/tests/test_example.py#L77

https://github.com/DiamondLightSource/python-copier-template/actions/runs/8631620883/job/23660687270#step:7:122

[joeshannon]

The type of error has changed?

Yes interesting I made a new venv and main is failing locally with the same for me now.

[joeshannon]

I think it's due to https://github.com/copier-org/copier/pull/1526 in the latest version of copier.