release-22.2: ui: install Cypress native binary just in time

[blathers-crl]

Backport 1/1 commits from #93800 on behalf of @sjbarag.

/cc @cockroachdb/release

---

Previously, the native binary for the UI end-to-end testing framework
Cypress[1] was installed immediately when starting any full build of
CockroachDB (i.e. anything that includes the web UI). This caused errors
on the non-Windows, non-Darwin, non-Linux operating systems that Cypress
doesn't support[2], including FreeBSD and illumos. Since those tests
aren't part of the core build or test suite, build failures are an
unnecessarily harsh failure mode. Download the native Cypress binary
only when necessary, restoring the ability for users on FreeBSD,
illumos, and others to build CockroachDB.

[1] https://cypress.io/
[2] https://docs.cypress.io/guides/getting-started/installing-cypress#Operating-System

Fixes: #87369

Release note (build change): The native binary for Cypress is now only
downloaded and installed when UI end- to-end tests are run, instead of
eagerly downloading it on all platforms at build-time. This restores
the ability for non-{Windows, Darwin, Linux} platforms like FreeBSD and
illumos to build CRDB without modifications, which broke in the initial
22.2 release.

---

Release justification: Non-production code changes

[blathers-crl]

Thanks for opening a backport.

Please check the backport criteria before merging:

• Patches should only be created for serious issues or test-only changes.
• Patches should not break backwards-compatibility.
• Patches should change as little code as possible.
• Patches should not change on-disk formats or node communication protocols.
• Patches should not add new functionality.
• Patches must not add, edit, or otherwise modify cluster versions; or add version gates.

If some of the basic criteria cannot be satisfied, ensure that the exceptional criteria are satisfied within.

• There is a high priority need for the functionality that cannot wait until the next release and is difficult to address in another way.
• The new functionality is additive-only and only runs for clusters which have specifically “opted in” to it (e.g. by a cluster setting).
• New code is protected by a conditional check that is trivial to verify and ensures that it only runs for opt-in clusters.
• The PM and TL on the team that owns the changed code have signed off that the change obeys the above rules.

Add a brief release justification to the body of your PR to justify this backport.

Some other things to consider:

• What did we do to ensure that a user that doesn’t know & care about this backport, has no idea that it happened?
• Will this work in a cluster of mixed patch versions? Did we test that?
• If a user upgrades a patch version, uses this feature, and then downgrades, what happens?

[cockroach-teamcity]

This change is 

[sjbarag]

Thanks for the quick re-review, @rickystewart !

bors r=rickystewart

[rickystewart]

bors r-

[craig]

Canceled.

[rickystewart]

No bors on release branches. :) Just click the merge button when checks have passed.

[github-actions]

Reminder: it has been 3 weeks please merge or close your backport!

[davepacheco]

It looks like 22.2.8 doesn't have this fix. Is it going to be in a future release? (Still hitting #93162 trying to build 22.2.8.)

[sjbarag]

It looks like 22.2.8 doesn't have this fix. Is it going to be in a future release? (Still hitting #93162 trying to build 22.2.8.)

😓 that's very embarrassing, I forgot to merge this. Let me get it back up to date and it'll be in 22.2.9. I'm so sorry @davepacheco !

[sjbarag]

Merged. Thanks for the reminder, @davepacheco, and sorry again for the super long delay!

[davepacheco]

No sweat. Thanks for the fix!