RFC: Remove obsolete database versions

[kean]

As surfaced in one of the recent posts by @mokagio, a few tests in the test suite take over a second, which is unacceptable. Fortunately, some are testing obsolete database version migrations from 5+ years ago. Removing these tests reduces the time it takes to run the test by 10 seconds (on M2 Pro).

CoreDataMigrationTests time: 10s → 0.5s (-9.5 s)

This PR only removes the tests, which is a safe call. But I suggest taking it a step further and removing the obsolete database version from 1 to 100. I measured the before and after, and the impact of eliminating these versions is measurable.

App size: 329.2 MB → 323.3 MB (-5.9 MB) (I measure the debug .ipa; the release per-device builds might differ)
MOM Compile time: 7.3 s → 3.0 s (-4.3 s)

Regression Notes

1. Potential unintended areas of impact: n/a
2. What I did to test those areas of impact (or what existing automated tests I relied on): n/a
3. What automated tests I added (or what prevented me from doing so): n/a

PR submission checklist:

• I have completed the Regression Notes.
• I have considered adding unit tests for my changes.
• I have considered adding accessibility improvements for my changes.
• I have considered if this change warrants user-facing release notes and have added them to RELEASE-NOTES.txt if necessary.

UI Changes testing checklist:

• Portrait and landscape orientations.
• Light and dark modes.
• Fonts: Larger, smaller and bold text.
• High contrast.
• VoiceOver.
• Languages with large words or with letters/accents not frequently used in English.
• Right-to-left languages. (Even if translation isn’t complete, formatting should still respect the right-to-left layout)
• iPhone and iPad.
• Multi-tasking: Split view and Slide over. (iPad)

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📲 You can test the changes from this Pull Request in Jetpack Alpha by scanning the QR code below to install the corresponding build.

	App Name	Jetpack Alpha
	Configuration	Release-Alpha
	Build Number	pr22284-171b38f
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	Warnings
⚠️	PR has more than 500 lines of code changing. Consider splitting into smaller PRs if possible.

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[crazytonyli]

What are the impacts of removing old database versions? If customers update an old version of the app that uses the deleted database version to the latest one, I guess the database migration would fail and they would lose their on-device data?

[kean]

If customers update an old version of the app that uses the deleted database version to the latest one, I guess the database migration would fail and they would lose their on-device data?

The number of customers on these versions is likely exceedingly small and can be ignored.

I haven't tested what happens, but it's likely going to lead to a crash. The PR that removes the old versions could tackles this. I think logging the user out and removing all local data would be a good option.

I highly doubt that if someone upgrades from version 85 to 251, it'll go smoothly. Chances are it'll either take forever, or crash, or lead to lost or corrupt data.