gh-38049: Fix broken docker/Dockerfile
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As mentioned in
https://github.com/sagemath/sage/pull/37856#issuecomment-2108157341 the
`Dockerfile` is broken by https://github.com/sagemath/sage/pull/37856.
This will be fixed in this PR.
More precisely we replace `install_scripts` by appending
`$SAGE_ROOT/local/bin` to the `bash` path variable. This does not affect
Sage but ensures easy access to `gap`, `maxima`, ... in a `bash`
session (see
https://github.com/sagemath/sage/pull/37856#issuecomment-2123031214 ff).
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### :hourglass: Dependencies
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URL: https://github.com/sagemath/sage/pull/38049
Reported by: Sebastian Oehms
Reviewer(s): Matthias Köppe
Committer
Release Manager
