Integrate seqrepo builds from github actions to vrs-in-a-box

* https://github.com/ga4gh/vrs-python/pull/584 will add seqrepo builds to the github actions/artifacts
* https://github.com/ga4gh/vrs-python/pull/569 fixes the healthcheck that was being hacked around in @ehclark seqrepo build
* Following on the merge of these we can integrate the builds from #584 into the vrs-in-a-box Dockerfile
* We can remove the duplicated seqrepo build in the vrs-in-a-box directory

When this issue closes I should be able to use the vrs-in-a-box docker image with seqrepo builds made in GitHub actions.

When vrs-in-a-box docker image has been pushed up then this should be sufficient for a release?

Nice-to-have clean up the Dockerfile that is in https://github.com/ga4gh/vrs-python/pull/584/files#diff-c3fdbd32f075cd18c6e330a8c0b9e4f43e1bec1de346169381745c40ec807333 since it presents basically the same thing as vrs-in-a-box Dockerfile.