build(deps): bump actions/download-artifact from 7 to 8

Bumps [actions/download-artifact](https://github.com/actions/download-artifact) from 7 to 8.
- [Release notes](https://github.com/actions/download-artifact/releases)
- [Commits](https://github.com/actions/download-artifact/compare/v7...v8)

---
updated-dependencies:
- dependency-name: actions/download-artifact
  dependency-version: '8'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

.github/workflows/main.yml

@@ -1324,7 +1324,7 @@ jobs:
         run: |
           echo "HOST_ARCH=$(uname -m | sed -e 's/x86_64/amd64/' -e 's/aarch64/arm64/')" >> $GITHUB_ENV
 
-      - uses: actions/download-artifact@v7
+      - uses: actions/download-artifact@v8
         with:
           name: cache
           path: ./cache
@@ -1332,7 +1332,7 @@ jobs:
       - name: load base
         run: xz -d -k < ./cache/base.tar.xz | docker import - dockcross/base:latest
 
-      - uses: actions/download-artifact@v7
+      - uses: actions/download-artifact@v8
         with:
           name: cache-${{ matrix.os }}
           path: ./cache
@@ -1524,13 +1524,13 @@ jobs:
           fetch-depth: 1
 
       - name: download ${{ matrix.image_name }}-amd64
-        uses: actions/download-artifact@v7
+        uses: actions/download-artifact@v8
         with:
           name: cache-${{ matrix.image_name }}-amd64
           path: ./cache-${{ matrix.image_name }}-amd64
 
       - name: download ${{ matrix.image_name }}-arm64
-        uses: actions/download-artifact@v7
+        uses: actions/download-artifact@v8
         with:
           name: cache-${{ matrix.image_name }}-arm64
           path: ./cache-${{ matrix.image_name }}-arm64