docs: Report builtin availability in other interpreters (#9105)

fix: #8228

Give the builtin reference a column per target — OPA, Wasm, and each
Rego implementation that publishes capabilities — so users can tell
whether a policy will run somewhere other than OPA itself.

Also a Github action that will run every monday and check the
capabilities have updated and open a PR. Could change it to monthly, but
I don't think Swift and Java have a set release schedule at the moment.
Will do a Java release next week and I can manually trigger this
workflow to make sure it works.

<img width="1156" height="865" alt="image"
src="https://github.com/user-attachments/assets/4f078e69-dd62-4cd7-a466-b75c78a094e4"
/>

<img width="1156" height="804" alt="image"
src="https://github.com/user-attachments/assets/84fa5350-2f3d-4fd5-ac07-a9bfd492d5cc"
/>

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Signed-off-by: Sebastian Spaink <sebastianspaink@gmail.com>