There are two copies of the same module, in tests/modules/purge_queuer_test and modules/purge_queuer_test

There are two copies of the same module, one in in tests/modules/purge_queuer_test and one in modules/purge_queuer_test. They are clearly the same module, as they both use the same files, and the description in the .info.yml file is the same.

name: 'Purge tests support (queuers)'
type: module
description: "Provides queuers for testing."
package: Testing
dependencies:
  - purge:purge

name: 'Purge tests support (queuers)'
type: module
description: "Provides queuers for testing."
package: Testing
dependencies:
  - purge:purge

Only one of those modules should be present.