operator: Add warning for old schema configuration

[btaani]

What this PR does / why we need it:
This PR adds a new warning condition to the LokiStack in case the object storage schema version is older than V13

Which issue(s) this PR fixes:
Fixes LOG-4548

Special notes for your reviewer:

Checklist

• Reviewed the CONTRIBUTING.md guide (required)
• Documentation added
• Tests updated
• CHANGELOG.md updated
  • If the change is worth mentioning in the release notes, add add-to-release-notes label
• Changes that require user attention or interaction to upgrade are documented in docs/sources/setup/upgrade/_index.md
• For Helm chart changes bump the Helm chart version in production/helm/loki/Chart.yaml and update production/helm/loki/CHANGELOG.md and production/helm/loki/README.md. Example PR
• 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

[periklis]

In general this PR goes into the right direction. A couple of suggestions for better UX:

• Keep the Warning condition that the user should upgrade to V13 if not done.
• Add another Warning condition that indicates that some schemas are off the retention limit.
• Move SchemaStatus into the ObjectStorageSchema struct to indicate which schemas are off the the retention limit.
• Add a custom metric that collects Loki stacks requiring a schema upgrade (i.e. lokistack_schema_upgrades_required). We can even write and deploy a custom alert for this: https://github.com/grafana/loki/blob/main/operator/internal/manifests/internal/alerts/prometheus-alerts.yaml)

[xperimental]

Overall a good start 👍
I have not tested this on a cluster yet, only looked at the source so far, but I added some comments already.

I second Peri's hint for an alert. I'm currently assuming that this is how the "insights" feature works in OpenShift.

[github-actions]

Trivy scan found the following vulnerabilities:

• HIGH, Target: docker.io/grafana/loki:main-724a841 (alpine 3.18.4), Type: alpine openssl: Incorrect cipher key and IV length processing in libcrypto3 v3.1.3-r0. Fixed in v3.1.4-r0
• HIGH, Target: docker.io/grafana/loki:main-724a841 (alpine 3.18.4), Type: alpine openssl: Incorrect cipher key and IV length processing in libssl3 v3.1.3-r0. Fixed in v3.1.4-r0
  \nTo see more details on these vulnerabilities, and how/where to fix them, please run docker build -t grafana/loki:main-724a841 -f cmd/loki/Dockerfile .
  trivy i grafana/loki:main-724a841 on your branch. If these were not introduced by your PR, please considering fixing them in via a subsequent PR. Thanks!

[xperimental]

I think the feature we're adding is the warning nudging the user to upgrade the schema:

Suggested change

	- [11158](https://github.com/grafana/loki/pull/11158) **btaani**: operator: Add support to add additional storage schema V13
	- [11158](https://github.com/grafana/loki/pull/11158) **btaani**: operator: Add warning for old schema configuration

[xperimental]

The new warning works nicely 👍

I left a few comments in the PR. I'll defer to @periklis for another pass.

[periklis]

LGTM and smoke testing working fine too. A couple of nits and one remaining question about removed tests.