Don't default to the post post type, if no other post types are selected

[dkotter]

Description of the Change

For Language Processing, if no post types are selected in the settings, we default to still using the post post type. If a user has decided to not select any post types, we should respect that decision and not run Language Processing on posts anyway.

Alternate Designs

None

Benefits

Settings will be respected and Language Processing won't happen on post types that haven't been selected

Possible Drawbacks

None

Verification Process

1. Go to the Language Processing settings
2. Deselect all the options under Post Types to Classify
3. Ensure the options below that are still enabled
4. Go and add a new post and save it
5. Ensure no classification happened and no Classify taxonomies are shown

Checklist:

• I have read the CONTRIBUTING document.
• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my change.
• All new and existing tests passed.

Applicable Issues

#246