Add dockerfiles to the public dir

[m1kola]

Summary

This is preparation to 1.6.1 release.

This covers recent OM and agent updates:

• CLOUDP-363744: Bump Cloud Manager version for MongoDB Agent container images for MMS release branch v20251210 #627
• CLOUDP-363986: Bump Ops Manager Container Image version to 7.0.20 #630
• CLOUDP-363991: Bump Ops Manager Container Image version to 8.0.17 #631

Note that OM 8.0.17 bump doesn't introduce a new agent image: we already have a Dockerfile for this OM version in public/dockerfiles/mongodb-agent/108.0.16.8895-1/ubi/Dockerfile.

Proof of Work

N/A: just copies of docker files.

Checklist

• Have you linked a jira ticket and/or is the ticket in the title?
• Have you checked whether your jira ticket required DOCSP changes?
• Have you added changelog file?
  • use skip-changelog label if not needed
  • refer to Changelog files and Release Notes section in CONTRIBUTING.md for more details

[m1kola]

Some of the CI jobs failed, but I'm going to merge because the files are not used at all and do not affect tests. CI failures seem to be flakes.