chore(deps): update docker/setup-buildx-action action to v4 (#179)

This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
| [docker/setup-buildx-action](https://github.com/docker/setup-buildx-action) | action | major | `v3` → `v4` |

---

### Release Notes

<details>
<summary>docker/setup-buildx-action (docker/setup-buildx-action)</summary>

### [`v4`](https://github.com/docker/setup-buildx-action/compare/v3...v4)

[Compare Source](https://github.com/docker/setup-buildx-action/compare/v3...v4)

</details>

---

### Configuration

📅 **Schedule**: Branch creation - At any time (no schedule defined), Automerge - At any time (no schedule defined).

🚦 **Automerge**: Disabled by config. Please merge this manually once you are satisfied.

♻ **Rebasing**: Whenever PR is behind base branch, or you tick the rebase/retry checkbox.

🔕 **Ignore**: Close this PR and you won't be reminded about this update again.

---

 - [ ] <!-- rebase-check -->If you want to rebase/retry this PR, check this box

---

This PR has been generated by [Renovate Bot](https://github.com/renovatebot/renovate).
<!--renovate-debug:eyJjcmVhdGVkSW5WZXIiOiI0My41MS4wIiwidXBkYXRlZEluVmVyIjoiNDMuNTEuMCIsInRhcmdldEJyYW5jaCI6Im1haW4iLCJsYWJlbHMiOltdfQ==-->

Reviewed-on: #179
Co-authored-by: Renovate Bot <renovate-bot@alexlebens.net>
Co-committed-by: Renovate Bot <renovate-bot@alexlebens.net>

.gitea/workflows/release-image-gitea.yml

@@ -55,7 +55,7 @@ jobs:
 
       - name: Set up Docker Buildx
         id: buildx
-        uses: docker/setup-buildx-action@v3
+        uses: docker/setup-buildx-action@v4
         with:
           driver: kubernetes
           driver-opts: |

.gitea/workflows/release-image-harbor.yml

@@ -55,7 +55,7 @@ jobs:
 
       - name: Set up Docker Buildx
         id: buildx
-        uses: docker/setup-buildx-action@v3
+        uses: docker/setup-buildx-action@v4
         with:
           driver: kubernetes
           driver-opts: |