I understand the switch to Npgsql Datasource, but what do the rest of the changes achieve? I'd rather see the other changes in a different PR if they're not necessary for the switch.

About the Datasource switch:

• Please try to keep using the DbContext and Datasource from the Program file instead of replacing them in the tests. Otherwise it leaves the actual Program's DB setup untested. Is it possible to still only change the configuration in the WebApplicationFactory ?

About the other changes:

• Respawn is an objectively inferior solution, it is slower (a simple in-memory file copy VS Respawn's multiple SQL requests). Does the current solution break with Datasource?
  To be fully honest, I'd rather do away with DB resets entirely and force tests to be written without them; because that leads to higher quality tests (it also runs way faster).
• Using async methods instead of sync methods has no advantage in this context

We still using this PR? We tweaking anything from it, if so?