chore(deps): update docker/build-push-action action to v6 (#34)

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This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
|
[docker/build-push-action](https://github.com/docker/build-push-action)
| action | major | `v5` -> `v6` |

---

### Release Notes

<details>
<summary>docker/build-push-action (docker/build-push-action)</summary>

###
[`v6`](https://github.com/docker/build-push-action/compare/v5...v6)

[Compare
Source](https://github.com/docker/build-push-action/compare/v5...v6)

</details>

---

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rebase/retry checkbox.

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---

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.github/workflows/commands.yaml

@@ -30,7 +30,7 @@ jobs:
       - uses: helm/kind-action@v1
         with:
           cluster_name: e2e
-      - uses: docker/build-push-action@v5
+      - uses: docker/build-push-action@v6
         with:
           tags: lke-operator:e2e
           build-args: VERSION=e2e

.github/workflows/image-docs.yaml

@@ -26,7 +26,7 @@ jobs:
         uses: docker/setup-buildx-action@v3
         with:
           platforms: linux/amd64,linux/arm64
-      - uses: docker/build-push-action@v5
+      - uses: docker/build-push-action@v6
         with:
           builder: ${{ steps.buildx.outputs.name }}
           platforms: linux/amd64,linux/arm64