Add GHC 9.6.1

[tfausak]

Fixes #31.

There's no HLS release yet. I don't know when to expect one.

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• I manually tested the code locally to make sure that it works.
• If there is documentation, I made sure it's accurate and up to date.
• If possible, I wrote automated tests for the new behavior.

[tfausak]

I should also consider updating the default version from 9.4.4 to 9.6.1. And removing 9.0.2, to follow the three major version release policy.

[tfausak]

This image is available as: public.ecr.aws/acilearning/haskell:9.6.1-09b78268b84fd4ad4f82e78c2e2a43eac6fafb5d

[tfausak]

I'm going to go ahead and merge this. Once there's an HLS release that supports GHC 9.6.1, I'll update the image to include it. Also at that point I'll update the default from 9.4.4 to 9.6.1.

I'll make a separate PR to remove 9.0.2.