Fix cuda docker image references

[csko]

Signed-off-by: Kornél Csernai [email protected]

Why are these changes needed?

There is no ubuntu20.04 image for cuda 10.2 and 10.1.

Related issue number

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• Testing Strategy
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[krfricke]

Btw, does the build still work with our docker files? (are they compatible with 18.04)?

[csko]

Btw, does the build still work with our docker files? (are they compatible with 18.04)?

I'm not super familiar with the build system, but in the 3.11 PR (https://github.com/ray-project/ray/pull/31170) it seemed to work with earlier.

[csko]

Would you be able to merge this? What's the best way to test this? cc @rickyyx

[krfricke]

Interesting - I'm wondering why this doesn't end up with a broken build at the moment.

[krfricke]

Anyway, I'll merge this for now, but we should investigate.