fix: complete Wishiwashi's Schooling form condition

[MiquelRForgeFlow]

Wishiwashi's School form declared the Schooling ability trigger but the Solo form did not, and the two weren't linked. This PR adds the trigger to the Solo form and set base_form on both so the transformation is described bidirectionally (like Minior's Shields Down).

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[Naramsim]

Thanks, I see that the form is changed based on the HP of the pokemon. I guess this is not something that the API can expose, right?

[pokeapi-machine-user]

A PokeAPI/api-data refresh has started. In ~45 minutes the staging branch of PokeAPI/api-data will be pushed with the new generated data.

The staging branch will be deployed in our staging environment and the entire API will be ready to review.

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[pokeapi-machine-user]

The updater script has finished its job and has now opened a Pull Request towards PokeAPI/api-data with the updated data.

The Pull Request can be seen deployed in our staging environment when CircleCI deploy will be finished (check the start time of the last build).