Drop electrsd's auto-download feature for good

[tnull]

... which requires a bunch of unnecessary dev dependencies, e.g., zip.

Instead we lean on the download_bitcoind_electrs.sh script also for local testing.

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 89.73%. Comparing base (9de7c1d) to head (4320f48).
Report is 4 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3020      +/-   ##
==========================================
- Coverage   89.73%   89.73%   -0.01%     
==========================================
  Files         122      122              
  Lines      101921   101922       +1     
  Branches   101921   101922       +1     
==========================================
  Hits        91463    91463              
- Misses       7770     7773       +3     
+ Partials     2688     2686       -2     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[TheBlueMatt]

Thanks! Now that we have a script, can we run download_bitcoind_electrs.sh directly from git CI yaml and then cache the outputs? That way we can avoid wasting all of bitcoincore.org's bandwidth.

[TheBlueMatt]

Any update here, looks like we currently can't build due to an MSRV bump in the time crate which this would fix.

[tnull]

Any update here, looks like we currently can't build due to an MSRV bump in the time crate which this would fix.

Uh, good to know. No update so far, but then I'll see to prioritize it (likely start of next week).

[tnull]

@TheBlueMatt I think this should be ready for review. So far it seems to work.

[tnull]

Mh, seems so far it didn't save the cached files, lets see if it does with the pushed fixup..

[TheBlueMatt]

Is it possible it only caches when running on a merge and not on PRs?

[tnull]

Is it possible it only caches when running on a merge and not on PRs?

I thought that first, too, but no, it also runs on PRs (cf. https://github.com/lightningdevkit/ldk-node/actions/caches). Actually all caches are branch-specific (so also of limited usefulness, tbh.). I previously included $HOME in path and that somehow didn't seem to work, but the fix that worked on LDK Node somehow seems to break CI here, so I'll need a few more tries to get this right I guess.

[TheBlueMatt]

so I'll need a few more tries to get this right I guess.

Alright, let us know when its there :)

[tnull]

Alright, let us know when its there :)

Alright, a thousand fixups and force-pushes later, this should be ready.

[tnull]

I added this exception to still allow running ./ci/ci-tests.sh locally without necessarily running the download script before. However, in CI we may want to fail here to avoid skipping tests if something with our CI setup is flaky.

@TheBlueMatt Do you have an opinion if it would be worth handing in a CI flag for this, or if we're fine skipping here?

[TheBlueMatt]

Hmm, yea, would be nice to have a CI flag, I think.

[tnull]

Done in a follow-up: #3240

[TheBlueMatt]

All just CI changes that are straightforward. More importantly, I need this to actually test things locally (cause I use MSRV often), so gonna just land this.