This PR addresses the out-of-memory (OOM) errors during the artifact upload stage in the CI pipeline.

[Atishyy27]

Key Changes:

• Action Updates: Upgraded actions/upload-artifact, actions/download-artifact, and actions/checkout to @v4 to ensure Node 20 compatibility and improved performance.
• Memory Optimization: Set compression-level: 0 for the hfuzz-corpus upload in build.yml. Disabling compression prevents the runner from exhausting memory while processing large fuzzing datasets.
• SemVer Fix: Added fetch-depth: 0 to the SemVer check workflow to prevent tool panics during baseline comparisons.

Note: I'm opening this as a Draft because jobs were stuck in the queue on my fork. I'd like to verify the fixes using the main repository's runners.

[ldk-reviews-bot]

I've assigned @joostjager as a reviewer!
I'll wait for their review and will help manage the review process.
Once they submit their review, I'll check if a second reviewer would be helpful.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 85.99%. Comparing base (647c3f7) to head (4748e7c).
⚠️ Report is 4 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #4478   +/-   ##
=======================================
  Coverage   85.98%   85.99%           
=======================================
  Files         159      159           
  Lines      105415   105415           
  Branches   105415   105415           
=======================================
+ Hits        90643    90647    +4     
- Misses      12255    12258    +3     
+ Partials     2517     2510    -7     

Flag	Coverage Δ
tests	85.99% <ø> (+<0.01%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

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

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[Atishyy27]

Hey @TheBlueMatt @carlaKC ,

All the primary CI checks have passed successfully on the main runners! The OOM issue is resolved with the compression-level: 0 fix (the fuzz job passed in ~74m).

The only failing check is the LDK Node Integration Tests. Looking at the logs, this seems to be a breakage caused by recent API changes in rust-lightning (PaymentForwarded event fields and splice_channel arguments) that haven't been reflected in ldk-node yet.

Let me know if you want me to squash the merge commits, or if this is good to go from my end once the ldk-node repo is updated!