[bug] Fix scalar data issue in plugin settings

[slessans]

For some reason when loading the config during plugin execution, ScalarData has already been converted which causes this code to throw an error. I added a check to take the ScalarData as is if it has already been converted.

Update: this seems to only happen when using ariadne_codegen.contrib.extract_operations.ExtractOperationsPlugin

[mat-sop]

Hey, it looks like the issue is that in this method we are directly modifying the argument config_dict. Instead of the proposed check, I would rather see a change that leaves the dict unmodified after the first call (for example by working on a copy)

[slessans]

@mat-sop updated!

[rafalp]

Thank you!