Fixing layout shape line dash validator #3375

[dvd7587]

Code PR

• I have read through the contributing notes and understand the structure of the package. In particular, if my PR modifies code of plotly.graph_objects, my modifications concern the codegen files and not generated files.
• I have added tests (if submitting a new feature or correcting a bug) or
  modified existing tests.
• For a new feature, I have added documentation examples in an existing or
  new tutorial notebook (please see the doc checklist as well).
• I have added a CHANGELOG entry if fixing/changing/adding anything substantial.
• For a new feature or a change in behaviour, I have updated the relevant docstrings in the code to describe the feature or behaviour (please see the doc checklist as well).

[nicolaskruchten]

Thanks for this pull request! Unfortunately, it was modifying auto-generated code and the full fix needs to be done "upstream" in the code generation machinery. I've implemented a more general fix in #3722 so I'll close this PR now.

[dvd7587]

Thanks for this pull request! Unfortunately, it was modifying auto-generated code and the full fix needs to be done "upstream" in the code generation machinery. I've implemented a more general fix in #3722 so I'll close this PR now.

@nicolaskruchten sorry I was not sure, even if I suspected it. thanks for fixing the issue ;)