Bump canonical/checkbox from 5.0.0 to 6.0.0 (infra) (#2123)

Bump canonical/checkbox from 5.0.0 to 6.0.0

Bumps [canonical/checkbox](https://github.com/canonical/checkbox) from 5.0.0 to 6.0.0.
- [Release notes](https://github.com/canonical/checkbox/releases)
- [Commits](7247f4b...bff743a)

---
updated-dependencies:
- dependency-name: canonical/checkbox
  dependency-version: 6.0.0
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

.github/workflows/dispatch_lab_job.yaml

@@ -44,7 +44,7 @@ jobs:
         run: echo "sha=$(git rev-parse HEAD)" >> $GITHUB_OUTPUT
 
       - name: Run the spec
-        uses: canonical/checkbox/.github/actions/checkbox_source_deb@7247f4bd68556af677e2debe88dc877a046870f9
+        uses: canonical/checkbox/.github/actions/checkbox_source_deb@bff743aad15fd2efad8a8b310e2cf9ed6bfae44d
         with:
           data_source: ${{ matrix.spec.data_source }}
           queue: ${{ matrix.spec.queue }}