Improve Dagger security by using TLS certificates

[Smana]

Enhancement Title

Secure access to Dagger with TLS

Summary

In the current architecture with Github Self-Hosted runners, dagger listens in plain HTTP.
It should be possible to expose TLS certificates using our internal PKI (Vault)

Benefits

Improve the security level, avoid leaking code.

Additional Context

Note that we mitigated the risk with a fine grained network policy which only grants the desired services.