chore(deps): update helm release cloudnative-pg to v0.21.4 (#469)

This PR contains the following updates:

| Package | Update | Change |
|---|---|---|
| [cloudnative-pg](https://cloudnative-pg.io) ([source](https://github.com/cloudnative-pg/charts)) | patch | `0.21.3` -> `0.21.4` |

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### Release Notes

<details>
<summary>cloudnative-pg/charts (cloudnative-pg)</summary>

### [`v0.21.4`](https://github.com/cloudnative-pg/charts/releases/tag/cloudnative-pg-v0.21.4)

[Compare Source](cloudnative-pg/charts@cloudnative-pg-v0.21.3...cloudnative-pg-v0.21.4)

CloudNativePG Operator Helm Chart

#### What's Changed

-   fix additionalEnv typo in deployment.yaml by [@&#8203;Stevenpc3](https://github.com/Stevenpc3) in cloudnative-pg/charts#305

**Full Changelog**: cloudnative-pg/charts@cloudnative-pg-v0.21.3...cloudnative-pg-v0.21.4

</details>

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Reviewed-on: https://git.internal/nrdufour/home-ops/pulls/469
Co-authored-by: Renovate <[email protected]>
Co-committed-by: Renovate <[email protected]>

kubernetes/main/apps/database/cloudnative-pg/app/helm-release.yaml

@@ -10,7 +10,7 @@ spec:
   chart:
     spec:
       chart: cloudnative-pg
-      version: 0.21.3
+      version: 0.21.4
       sourceRef:
         kind: HelmRepository
         name: cloudnative-pg