Fixed #35407 -- Cached model's Options.swapped.

[adamchainz]

Trac ticket number

ticket-35407

Branch description

Optimization per ticket.

Checklist

• This PR targets the main branch.
• The commit message is written in past tense, mentions the ticket number, and ends with a period.
• I have checked the "Has patch" ticket flag in the Trac system.
• I have added or updated relevant tests.
• I have added or updated relevant docs, including release notes if applicable.
• I have attached screenshots in both light and dark modes for any UI changes.

[nessita]

Thank you @adamchainz! Could you please add a test to ensure the new approach works properly? Thank you!

[adamchainz]

Thank you @adamchainz! Could you please add a test to ensure the new approach works properly? Thank you!

Done. The existing tests covered most or all cases already, implicitly, but I added explicit tests in the model_meta module.

[sarahboyce]

Thank you!