fix(blooms): Do not restart builders when planner disconnects (backport k227)

[loki-gh-app]

Backport 7669385 from #14783

---

What this PR does / why we need it:

Before this PR, when the planner restarted, all builders errored and restarted as well. This happened becvause even though we had a backoff mechanism, it was not reset when we could connect at least once succesfully.

This PR fixes this so builders just retry connecting to the planner again. We handle the EOF error we get when the planner disconnects to reset the backoff and start again.

Here's an example:

While the planner is down, there are no restarts

But we do print errors

We did this test using this backoff config:

bloom_build+: {
  builder+: {
    backoff_config+: {
      min_period: '1s',
      max_period: '1m',
    },
  },
},

Special notes for your reviewer:

Checklist

• Reviewed the CONTRIBUTING.md guide (required)
• Documentation added
• Tests updated
• Title matches the required conventional commits format, see here
  • Note that Promtail is considered to be feature complete, and future development for logs collection will be in Grafana Alloy. As such, feat PRs are unlikely to be accepted unless a case can be made for the feature actually being a bug fix to existing behavior.
• Changes that require user attention or interaction to upgrade are documented in docs/sources/setup/upgrade/_index.md
• If the change is deprecating or removing a configuration option, update the deprecated-config.yaml and deleted-config.yaml files respectively in the tools/deprecated-config-checker directory. Example PR