ui: type check target pulls 178MB off a 3rd party vendor upon every CI run, and fails if upstream is unavailable

[knz]

This is a variant of #51543 and is currently causing flakes in CI.

Describe the problem

The pkg/ui/workspaces/e2e-tests target downloads the following URL every time it runs:

https://download.cypress.io/desktop/10.3.0?platform=linux&arch=x64

I went and checked and that is a 178MB archive to download (compressed).

The archive is not cached, unlike the builder image, so that's a mandatory ingress cost on every CI run.

Moreover, today the upstream HTTP server is saying "no" and is causing all the CI runs to fails. (example)

Expected behavior

The archive should be embedded in the builder image, and/or the fetch should use a cached copy if it was already downloaded earlier on the TC agent.

(At the very least we should be fetching from a proxy cache inside the CRL infra so that the CI downloads are internal to GCP).

cc @sjbarag @jlinder @rickystewart for triage.

Epic DEVINF-109

Jira issue: CRDB-30805

[rickystewart]

For CI, this should be fixed by #109157. Please re-open if the problem seems to recur.