chore(deps): update docker/build-push-action action to v6.16.0 (rnaveiras#340)

This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
|
[docker/build-push-action](https://redirect.github.com/docker/build-push-action)
| action | minor | `v6.15.0` -> `v6.16.0` |

---

### Release Notes

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

###
[`v6.16.0`](https://redirect.github.com/docker/build-push-action/compare/v6.15.0...v6.16.0)

[Compare
Source](https://redirect.github.com/docker/build-push-action/compare/v6.15.0...v6.16.0)

</details>

---

### Configuration

📅 **Schedule**: Branch creation - "before 9am on Saturday" in timezone
Europe/London, Automerge - At any time (no schedule defined).

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

♻ **Rebasing**: Whenever PR becomes conflicted, 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

---

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Author: rnaveiras

.github/workflows/build.yaml

@@ -110,7 +110,7 @@ jobs:
             type=ref,event=pr
             type=ref,event=tag
             type=semver,pattern={{version}}
-      - uses: docker/build-push-action@471d1dc4e07e5cdedd4c2171150001c434f0b7a4 # v6.15.0
+      - uses: docker/build-push-action@14487ce63c7a62a4a324b0bfb37086795e31c6c1 # v6.16.0
         with:
           cache-from: type=gha
           cache-to: type=gha,mode=max