Since we're already setting `wordpress_oauth2` using the `option :name`
command in the `OmniAuth::Strategies::Wordpress` class, Devise can
automatically find the strategy. However, it wasn't working because we
were passing a string instead of a symbol.
Even though we don't load this file with Zeitwerk, we're doing it for
consistency.
If we tried to load this file using Zeitwerk, without this change we'd
get an error:
```
NameError: uninitialized constant OmniauthWordpress
```
