Switch to using buf to manage protobuf code

[mem]

Signed-off-by: Marcelo E. Magallon [email protected]

[mem]

This seems nice! I guess we're hoping to stop importing the agent in the -api and instead use a dependency on buf.build/grafana/synthetic-monitoring-agent?

Was there a discussion on this that I should catch up on?

For now I just want to get rid of a custom build process and gain access to the backwards compatibility verification tool.

There wasn't a discussion about this.