CockroachDB CI does not properly cache dependencies

[knz]

• cdc/bank roachtest pull 260MB off a 3rd party vendor upon every CI run, and fails if upstream unavailable cdc/bank roachtest pull 260MB off a 3rd party vendor upon every CI run, and fails if upstream unavailable #51543
• Example-ORMs pulls files from 3rd party vendors on every CI run, and fails if upstream is unavailable Example-ORMs pulls files from 3rd party vendors on every CI run, and fails if upstream is unavailable #52342
• roachtest: jepsen tests pull code from github upon every run roachtest: jepsen tests pull code from github upon every run #62023
• roachtest: jepsen tests pull code from clojar upon every run roachtest: jepsen tests pull code from clojar upon every run #62066
• acceptance: all acceptance tests that use docker download images from docker-io upon every use acceptance: all acceptance tests that use docker download images from docker-io upon every use #62024
• CI pulls from npmjs registry upon every run and fails if npmjs reg is not available CI pulls from npmjs registry upon every run and fails if npmjs reg is not available #69333

Previously tracked here: https://github.com/cockroachdb/dev-inf/issues/39
Unsure where this is tracked now.

Epic DEVINF-109

Jira issue: CRDB-9549

[github-actions]

We have marked this issue as stale because it has been inactive for
18 months. If this issue is still relevant, removing the stale label
or adding a comment will keep it active. Otherwise, we'll close it in
10 days to keep the issue queue tidy. Thank you for your contribution
to CockroachDB!

[knz]

still relevant