`mage notice` command hangs infinitely

[ChrsMark]

From latest main the mage notice command hangs forever like below:

➜  elastic-agent git:(hints_based_autodiscovery_mappings) ✗ mage notice
>> Generating NOTICE
>> fmt - go mod tidy
>> fmt - go mod download
>> fmt - go list
>> fmt - go run

This blocks us from updating any dependencies cause we cannot update the NOTICE.txt file accordingly and the CI will fail in any case (ie at #698).

[belimawr]

I did some investigating and found two issues:

1. There is a race condition when calling go-licence-detector
2. There is an issue with the arguments to go-licence-detector, or it's not behaving as expected.

I'll create a PR fixing at least the first issue.

[belimawr]

I know very little about go-licence-detector, so I can't help much to fix the issue with it. Maybe @cmacknz knows more or could help to find someone to look at it.

[cmacknz]

This problem feels familiar and I suspect it might have been fixed in the magefile of another project, let me try to track that down.

[cmacknz]

This what beats does: https://github.com/elastic/beats/blob/cf10d315d0f4d7fbe5893d65532078c3adbbd6b7/Makefile#L171

[cmacknz]

We also implement this different in elastic-agent-libs which is what most of the new repositories use: https://github.com/elastic/elastic-agent-libs/blob/ee6ce69b6f17a29307878527768f687d4d77faef/magefile.go#L83

[belimawr]

Thanks @cmacknz! I had looked at the magefile.go from Beats/Filebeat and it looks to be the same as the Elastic-Agent is doing in terms of parameters to go-licence-detector :/

Anyway, I'll give it another shot.