Fix issue where device connection check is not memoized

[bjester]

Summary

I just happened to notice that a bit of code was incorrect, within the device connection checker logic. It should be using a memoized function to ensure the frontend doesn't query for connection testing too often for a device.

References

https://learningequality.slack.com/archives/CB37UM23A/p1705105053832879?thread_ts=1705100642.965639&cid=CB37UM23A

Reviewer guidance

I ran Kolibri and tested that the device selection modal still worked and tested connections appropriately.

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Testing checklist

• Contributor has fully tested the PR manually
• If there are any front-end changes, before/after screenshots are included
• Critical user journeys are covered by Gherkin stories
• Critical and brittle code paths are covered by unit tests

PR process

• PR has the correct target branch and milestone
• PR has 'needs review' or 'work-in-progress' label
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• If this is an important user-facing change, PR or related issue has a 'changelog' label
• If this includes an internal dependency change, a link to the diff is provided

Reviewer checklist

• Automated test coverage is satisfactory
• PR is fully functional
• PR has been tested for accessibility regressions
• External dependency files were updated if necessary (yarn and pip)
• Documentation is updated
• Contributor is in AUTHORS.md

[github-actions]

Build Artifacts

Asset type	Download link
PEX file	kolibri-0.16.0b11.dev0_git.11.g212f9f43.pex
Windows Installer (EXE)	kolibri-0.16.0b11.dev0+git.11.g212f9f43-unsigned.exe
Debian Package	kolibri_0.16.0b11.dev0+git.11.g212f9f43-0ubuntu1_all.deb
Mac Installer (DMG)	kolibri-0.16.0b11.dev0+git.11.g212f9f43-0.3.0.dmg
Android Package (APK)	kolibri-0.16.0b11.dev0+git.11.g212f9f43-0.1.0-debug.apk
TAR file	kolibri-0.16.0b11.dev0+git.11.g212f9f43.tar.gz
WHL file	kolibri-0.16.0b11.dev0+git.11.g212f9f43-py2.py3-none-any.whl

[rtibbles]

No regressions observed - network connections appear to be checked not too frequently.