register-runners: adjust to be more flexible

Instead of hardcoding 2 runners to be registered, you can add profiles
to a directory to specify what runners should be registered.
7 jobs for remove-docker-compose in 6 minutes and 27 seconds (queued for 1 second)
Status Job ID Name Coverage
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lint

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  Build
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aarch64 ci-docker-image docker-alpine
build-aarch64

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armv7 ci-docker-image docker-alpine
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ppc64le ci-docker-image docker-alpine
build-ppc64le

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s390x ci-docker-image docker-alpine
build-s390x

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x86 ci-docker-image docker-alpine
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x86_64 ci-docker-image docker-alpine
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