Fix wp_json_file_decode() PHP notice

[crodriguezbrito]

Proposed changes

This PR will fix the notice related to the wp_json_file_decode() function

PHP Notice: wp_json_file_decode(): File doesn't exist!

This fix updates the file path for locating the theme-i18.json file, ensuring that it retrieves the file from the correct location.

Type of Change

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation Update (if none of the other choices apply)

Video

Checklist

• I have read the CONTRIBUTING doc
• I have viewed my change in a web-browser
• Linting and tests pass locally with my changes
• I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation (if appropriate)

Further comments