fix: replace object.mixin with Object.assign

[derwehr]

The basics

• I branched from develop
• My pull request is against develop
• My code follows the style guide
• I ran npm run format and npm run lint

The details

Resolves

#5914

Proposed Changes

Replaces all uses of object.mixin with Object.assign

Behavior Before Change

Behavior After Change

Reason for Changes

see #5914

Test Coverage

Documentation

Additional Information

Things I didn't do, because I was unsure if they're needed or wanted:

• update any documentation
• declare object.mixin as deprecated

[BeksOmega]

Thank you so much for posting this! And thank you for removing the goog.require calls as well.

I think we should definitely deprecate the object.mixin function, so that we don't accidentally use it in the future. Here is a good example of how to deprecate something.

1. Add an @deprecated tag recording what to use instead, and when the function was deprecated.
2. Add a call to Blockly.utils.deprecation.warn with similar info. The deletionDate should be May 2023.

Thank you again for posting this fix! We really appreciate it =)

[BeksOmega]

Perfect! Thank you again :D