Method for providing certificates for private GitLab server

[gcatto]

Is your feature request related to a problem? Please describe.
I have a private GitLab server and when I try to use scorecard with it via the docker image, I get a tls: failed to verify certificate: x509: certificate signed by unknown authority error. I looked at the image, but it seems like that since it is using chainguard, I cannot "just" extend the image, add my certs, and such.

Describe the solution you'd like
A method for including/providing certificates for a private GitLab repo.

Describe alternatives you've considered
Building my own image equivalent of https://github.com/ossf/scorecard/blob/main/Dockerfile but with my certs on it.

Additional context
None