Fix: Reduce Docker image size

[stumpylog]

Description:

Related issue (if applicable): None

Reduces the Docker image compressed size to about 10% of the original size. In short, the cleanup was not actually doing anything, as it happens on a different image layer from where the files being removed were added.

The builder stage is now responsible for producing the wheel for cryptography. It also installs the minimal profile from rustup, for a slight speed up as well. No cleanup is necessary here, as it is discarded when done

The runtime installs only the necessary packages and consumes the built wheel. aptget leftovers are properly cleaned up in the same layer.

Everything else related to the application itself remains unchanged and running the image locally seems to work, serving the dashboard and such.

Checklist

• [x] The code change is tested and works locally.
• [x] There is no commented out code in this PR.
• [ ] No lint errors (use flake8)
• [ ] Tests added

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Comparison is base (46d9533) 95.16% compared to head (95dcfc3) 95.16%.

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Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #150 +/- ## ======================================= Coverage 95.16% 95.16% ======================================= Files 7 7 Lines 703 703 ======================================= Hits 669 669 Misses 34 34 ```

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