Occasioanl 'java.util.ConcurrentModificationException' errors

### Description of the bug

Originally reported by @Midnighter and seen on Github actions, but I just replicated it now.

Also happening in other repositories: https://github.com/nextflow-io/nextflow/issues/6410

### Command used and terminal output

```console

```

### Relevant files

_No response_

### System information

_No response_