Release v0.1.21

What's Changed

• Dont set always holesky teku as validatorUrl by @Marketen in #391
• use https in validatorUrl if teku by @Marketen in #392
• fix url typo by @Marketen in #393
• use old domain for teku due to tls cert by @Marketen in #394
• Return to frontend raw data by @pablomendezroyo in #390
• Fix unit testing by @pablomendezroyo in #395
• Bump express to ^5.0.0 by @pablomendezroyo in #396
• Implement prometheus api client by @pablomendezroyo in #397
• Add brain API by @pablomendezroyo in #398
• Use Dependency Injection instead of exporting instances from app entrypoint by @pablomendezroyo in #399
• Fix lukso TLS cert by @pablomendezroyo in #401

Full Changelog: 0.1.20...0.1.21