No blobbing is used in the cited Dockerfiles.
They did, but Clayton fixed it for you: https://github.com/openshift/router/commit/1a473a27c069dd215b2a79fda7ed25c39bc33182#diff-5dd1f404b476c53f76ed0f57f9fd9601
And it looks like he didn't backport it for you, so you still need to fix older branches so they can also be built on our CI system. I'm reopening this to track the backporting work, but really you need to clone it back to 4.4/4.3/etc and make the changes there (and re-close this, preferably via a verification route rather than a not a bug route, since changes were actually made to resolve it).
The back ports were all opened, but none of the bugs were associated to this one (or clones of this one). So I'll sort out the bugzilla mess.
Checked the four docker files and all of them have been fixed.
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://access.redhat.com/errata/RHBA-2020:2409