Update chartjs to v2.9.3

[XhmikosR]

By submitting this pull request, I confirm the following: {please fill any appropriate checkboxes, e.g: [X]}

{Please ensure that your pull request is for the 'devel' branch!}

• I have read and understood the contributors guide, as well as this entire template.
• I have made only one major change in my proposed changes.
• I have commented my proposed changes within the code.
• I have tested my proposed changes.
• I am willing to help maintain this change if there are issues with it later.
• I give this submission freely and claim no ownership.
• It is compatible with the EUPL 1.2 license
• I have squashed any insignificant commits. (git rebase)
• I have Signed Off all commits. (git commit --signoff)

---

Fixes #1345.

[XhmikosR]

@DL6ER Are you OK with the changes in the axes? It seems to show more values now.

[DL6ER]

Yes, that's fine. I checked it does automatically adapt when there are too many labels

[XhmikosR]

OK, if you like it. Because this is what I get on my WSL instance which doesn't have a lot of requests

[DL6ER]

This seems to be the standard behavior for the updated Chart.js. We do not mess with axis ticks anywhere.

[XhmikosR]

Ok, so we are merging?

[DL6ER]

Yes, I am waiting for the last test to pass. Feel free to overwrite it if it gets stale, however.

[pralor-bot]

This pull request has been mentioned on Pi-hole Userspace. There might be relevant details there:

https://discourse.pi-hole.net/t/pi-hole-5-1-released/35577/1