Add cmip6 and obs4mips data for ESMValTool ozone diagnostic

[axel-lauer]

Description

Add cmip6 sample and obs4mips data for ESMValTool ozone diagnostic.

Checklist

Please confirm that this pull request has done the following:

• Data registry up to date (regenerate if necessary via the regenerate action)
• Documentation added (where applicable)
• Changelog item added to changelog/

[lewisjared]

The sample data generation currently only works for non-forked branches. The amount of data we need is much larger than the GH cache so we are currently self-hosting this. We are figuring out how to handle this better (open to ideas!)

I just invited you to the Climate-REF org, but can make a branch on this repo tomorrow so we can run the GH action to regenerate.