Cut down Docker image sizes

[ddundo]

Description

Currently unnecessary files are removed in a separate layer in Dockerfile.firedrake-env, which doesn't reduce the final image size. In this PR I removed them inside the build layer, so the image size is reduced by 3GB (from 6.58GB to 3.57GB).

[connorjward]

This is a great spot. Thanks.

[connorjward]

Looks like this is running into repo permissions issues. I will copy your branch into firedrakeproject and open my own PR.

[ddundo]

Looks like this is running into repo permissions issues. I will copy your branch into firedrakeproject and open my own PR.

Thanks @connorjward! And yeah, I tried to copy some of the CI changes I saw in your yesterday's PR.

[connorjward]

#3917

[connorjward]

I am happy with this. If you remove the CI-specific changes I will approve and merge this. Thanks again!

[ddundo]

I am happy with this. If you remove the CI-specific changes I will approve and merge this. Thanks again!

Done! Thanks for looking into this so fast

[ddundo]

Btw @connorjward I just noticed that all subsequent images (firedrake-vanilla etc.) were built with firedrake-env:latest as base in the CI, and not firedrake-env:testing as I would have expected. Ignore me if that's all good

[connorjward]

Btw @connorjward I just noticed that all subsequent images (firedrake-vanilla etc.) were built with firedrake-env:latest as base in the CI, and not firedrake-env:testing as I would have expected. Ignore me if that's all good

Yeah I wasn't sure why that happened but the changes you introduced were so minor I wasn't concerned. The CI demonstrated that Dockerfile.env ran fine which was what mattered.