The following bug has been logged on the website:

Bug reference: 18674
Logged by: Alexander Lakhin
Email address: exclusion(at)gmail(dot)com
PostgreSQL version: 17.0
Operating system: Ubuntu 22.04
Description:

The following script:
CREATE ACCESS METHOD ham TYPE TABLE HANDLER heap_tableam_handler;
CREATE TABLE pt (a int) PARTITION BY LIST (a) USING ham;
DROP ACCESS METHOD ham;

ends successfully, with the access method dropped, though then:
CREATE TABLE tp1 PARTITION OF pt FOR VALUES IN (1);

fails with
ERROR: cache lookup failed for access method 16385

Whilst
CREATE TABLE t (a int) USING ham;
DROP ACCESS METHOD ham;

fails with
ERROR: cannot drop access method ham because other objects depend on it
DETAIL: table t depends on access method ham
HINT: Use DROP ... CASCADE to drop the dependent objects too.

Reproduced starting from 374c7a229.