This was a very good point on https://github.com/dagster-io/dagster/pull/4331 - if you specify a secret on the run launcher, secrets on the executor should be additive, not... replace-i-tive.
Should dedup the the lists? Or at least test behavior with duplicates (I think that's already happening in the integration test?)
What executor config are we leaving out for this test?
@alangenfeld or @rexledesma if you wouldn't mind reviewing this since johann is out that week I would be very grateful
the or  is a bit odd - exc_cfg.get should return a list since it's typed by config, right?
env_config_maps is Noneable so I believe it can be None, for better or worse
(was more relevant when it would replace the launcher config when it was set though - since in that case None was distinct from )