fix: repo build errors and vscode issues

[JessicaBarh]

Description

• Fixes repo build errors (vulnerabilities and unpinned upstream image causing a dependency conflict)
• Fixes vscode not showing in french and having broken python support

Resolves #249, #247, #240 also #257

Tests / Quality Checks

Automated Testing/build and deployment

• Does the image pass CI successfully (build, pass vulnerability scan, and pass automated test suite)?
• If new features are added (new image, new binary, etc), have new automated tests been added to cover these?
• If new features are added that require in-cluster testing (e.g. a new feature that needs to interact with kubernetes), have you added the auto-deploy tag to the PR before pushing in order to build and push the image to ACR so you can test it in cluster as a custom image?

JupyterLab extensions

• Are all extensions "enabled" (jupyter labextension list from inside the notebook)?

VS Code tests

• Does VS Code open?
• Can you install extensions?

Code review

• Have you added the auto-deploy tag to your PR before your most recent push to this repo? This causes CI to build the image and push to our ACR, letting reviewers access the built image without having to create it themselves
• Have you chosen a reviewer, attached them as a reviewer to this PR, and messaged them with the SHA-pinned image name for the final image to test (e.g. k8scc01covidacr.azurecr.io/machine-learning-notebook-cpu:746d058e2f37e004da5ca483d121bfb9e0545f2b)?

[JessicaBarh]

New vulnerability found: CVE-2021-23334

according to the comments in this issue, it's a false positive and in the process of being revoked.

Vulnerability withdrawn GHSA-8v27-2fg9-7h62

[ca-scribner]

otherwise lgtm

[Jose-Matsuda]

There's some annoying behaviour happening right now with the French Language extension. It is installed, but vscode is not recognizing it as a "display language" option. Using the older version of the French extension did not work either.

I think the reason is the languagepacks.json not getting created properly in the /etc/share/code-server/ directory.
Compare our current

To what I get when I try running locally

I'll try this out in a bit, as well as maybe make it such that it would use the French file on startup (previously we just installed it and say the LANG variable had no impact on how code-server was starting up)

While not helpful right now, the folks at cdr are looking into doing this sort of thing automatically coder/code-server#3173

[ca-scribner]

I was going to do a review but I'll hold off on this till Jose reports back :)

[Jose-Matsuda]

All right looks like we good would also close #240 also closes #257

[ca-scribner]

Added two suggested comments/changes to comments

Also pushed a change moving the libpdfbox-java uninstall up in the stack. I want CI to build successfully in case I broke something, so I haven't approved yet. Will approve when that is done

[ca-scribner]

Suggested change

	# as simply using the tag does not allow stability and reproducibility as these image tags are updated frequently.
	# the BASE_VERSION pinned below corresponds to a git commit SHA for image jupyter/datascience-notebook:r-4.0.3
	# Using the git-SHA is unique and immutable. it can be obtained by running `docker inspect repo/imagename:tag@digest`
	# Docker-stacks version tags (eg: `r-4.0.3`) are LIVE images that are frequently updated. To avoid unexpected
	# image updates, pin to the docker-stacks git commit SHA tag.
	# It can be obtained by running `docker inspect repo/imagename:tag@digest` or from
	# https://github.com/jupyter/docker-stacks/wiki

[ca-scribner]

team effort! :D lgtm

[ca-scribner]

Leaving for @JessicaBarh to merge once tests pass. Jess please make sure to squash on merge (I'm terrible at remembering that...)