debian10 images are being deprecated

[Appu Goundan]

If you use any images based on debian10, they will be deprecated Sept 1st (earliest). We will no longer build or update these images.

This is inline with our support policy here: https://github.com/GoogleContainerTools/distroless/blob/main/SUPPORT_POLICY.md

And also with debian's EOL: https://wiki.debian.org/DebianReleases#Production_Releases

We do not intend on supporting the LTS or ELTS debian10 builds on distroless.