fix(helm): update chart grafana ( 7.3.8 → 7.3.9 ) (#3488)

This PR contains the following updates:

| Package | Update | Change |
|---|---|---|
| [grafana](https://grafana.com)
([source](https://togithub.com/grafana/helm-charts)) | patch | `7.3.8`
-> `7.3.9` |

---

### Release Notes

<details>
<summary>grafana/helm-charts (grafana)</summary>

###
[`v7.3.9`](https://togithub.com/grafana/helm-charts/releases/tag/grafana-7.3.9)

[Compare
Source](https://togithub.com/grafana/helm-charts/compare/grafana-7.3.8...grafana-7.3.9)

The leading tool for querying and visualizing time series and metrics.

#### What's Changed

- \[grafana] fix: lookup volumename on pvc by
[@&#8203;guilhem](https://togithub.com/guilhem) in
[grafana/helm-charts#3041

#### New Contributors

- [@&#8203;guilhem](https://togithub.com/guilhem) made their first
contribution in
[grafana/helm-charts#3041

**Full Changelog**:
grafana/helm-charts@grafana-sampling-0.1.1...grafana-7.3.9

</details>

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Co-authored-by: repo-jeeves[bot] <106431701+repo-jeeves[bot]@users.noreply.github.com>

kubernetes/main/apps/observability/grafana/app/helm-release.yaml

@@ -9,7 +9,7 @@ spec:
   chart:
     spec:
       chart: grafana
-      version: 7.3.8
+      version: 7.3.9
       sourceRef:
         kind: HelmRepository
         name: grafana-charts