bump db-keystore to v0.4.0

[stevelr]

• bumped dependency db-keystore to v0.4.0
• moved 'fastrand' and 'zeroize' to dev-dependencies since they are only used by examples.
• ran cargo update

[stevelr]

Looks like github runners experiencing problems - you may need to wait a bit and retry the jobs
https://status.github.com

Update - Our upstream provider has applied a mitigation to address queuing and job failures on hosted runners.
Telemetry shows improvement, and we are monitoring closely for full recovery.
Feb 02, 2026 - 22:53 UTC

Update - We continue to investigate failures impacting GitHub Actions hosted-runner jobs.
We're waiting on our upstream provider to apply the identified mitigations, and we're preparing to resume job processing as safely as possible.
Feb 02, 2026 - 22:10 UTC