Add testing method to requirement

Requirements should store the testing method.
Available methods: test, analysis, inspection, and review of design

I propose that you read all the labels that you find in a requirement/issue (except "requirement" of course) and that you display them as tags, independently of their meaning.
And when user creates a requirement/issue, let him also enter tags and translate them to labels on gitlab

You know a bit like the tags on stack overflow:

And those tags can be used for filtering as well.