chore(deps): update docker/bake-action action to v6 (#3199)

This PR contains the following updates:

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

---

### Release Notes

<details>
<summary>docker/bake-action (docker/bake-action)</summary>

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

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

</details>

---

### Configuration

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

🚦 **Automerge**: Enabled.

♻ **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 was generated by [Mend Renovate](https://mend.io/renovate/).
View the [repository job
log](https://developer.mend.io/github/libretime/libretime).

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.github/workflows/container.yml

@@ -86,7 +86,7 @@ jobs:
           echo "LIBRETIME_VERSION=$(cat VERSION | tr -d [:blank:])" >> $GITHUB_ENV
 
       - name: Build
-        uses: docker/bake-action@v5
+        uses: docker/bake-action@v6
         with:
           pull: true
           push: ${{ github.event_name == 'push' }}