feat(deploy-queue): Add heartbeat

[Shugenya]

Deploy Queue cannot handle deployment cancellation in case there is runner failure. This results in stuck deployment that is blocking other deployments.

For those cases we'd like to introduce heartbeat - logic that is running and marking deployment as alive.

In this PR:

• new column heartbeat_timestamp in deployments table
• new CLI command for heartbeat
• cancel stale deployments (where heartbeat is over the timeout threshold) before querying blocking deployments

[jcgruenhage]

good start :)

[Shugenya]

@jcgruenhage
I am trying to understand the compatibility test failure - it's failing for tag v0.6.0.
When checking the files in this version: https://github.com/neondatabase/dev-actions/blob/deploy-queue-v0.6.0/deploy-queue/src/util/database.rs#L49 I see that .set_ignore_missing(true) was not yet used here. So the error is expected.
I don't understand why do we use 0.6.0 in the compatibility tests then? I assumed the idea was to use versions that already have that setting and make sure they still work even if there are new migrations applied.

[jcgruenhage]

Good progress! :)

[bayandin]

Didn't check the Rust part (JC did it), but the comments are resolved and review looks ok — LGTM

We want to merge this PR