CI: remove admin user configs to use defaults in testing

4 jobs for json-testdata in 14 minutes and 20 seconds (queued for 5 seconds)
Status Job ID Name Coverage
  Build
passed #1397147
build

00:02:02

 
  Test
passed #1397148
test

00:08:13

87.2%
passed #1397149
test:files_postgres

00:01:38

 
  Deploy
passed #1397150
deploy

00:04:04