Bump actions/download-artifact from 5 to 6

Bumps [actions/download-artifact](https://github.com/actions/download-artifact) from 5 to 6.
- [Release notes](https://github.com/actions/download-artifact/releases)
- [Commits](actions/download-artifact@v5...v6)

---
updated-dependencies:
- dependency-name: actions/download-artifact
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

.github/workflows/docker.yml

@@ -62,7 +62,7 @@ jobs:
             with:
                 fetch-depth: 0
         -   name: Restore docker image
-            uses: actions/download-artifact@v5
+            uses: actions/download-artifact@v6
             with:
                 name: docker
                 path: ${{ env.IMAGE }}
@@ -105,7 +105,7 @@ jobs:
             with:
                 fetch-depth: 0
         -   name: Restore docker image
-            uses: actions/download-artifact@v5
+            uses: actions/download-artifact@v6
             with:
                 name: docker
                 path: ${{ env.IMAGE }}
@@ -141,7 +141,7 @@ jobs:
             with:
                 fetch-depth: 0
         -   name: Restore docker image
-            uses: actions/download-artifact@v5
+            uses: actions/download-artifact@v6
             with:
                 name: docker
                 path: ${{ env.IMAGE }}