The product page for the Thingy53 only shows hardware files for the v0.8.0 board revision, not the 1.0.0 or v1.1.0 board revisions.
https://www.nordicsemi.com/Products/Development-hardware/Nordic-Thingy-53/Downloads?lang=en#infotabs
The relevant page on docs.nordicsemi.com just links back to the product page: https://docs.nordicsemi.com/bundle/ug_thingy53/page/UG/thingy53/kit_content/kit_content.html#kit_content