Bump actions/download-artifact from 7.0.0 to 8.0.0

Bumps [actions/download-artifact](https://github.com/actions/download-artifact) from 7.0.0 to 8.0.0.
- [Release notes](https://github.com/actions/download-artifact/releases)
- [Commits](actions/download-artifact@37930b1...70fc10c)

---
updated-dependencies:
- dependency-name: actions/download-artifact
  dependency-version: 8.0.0
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

.github/workflows/ftl-build.yml

@@ -159,7 +159,7 @@ jobs:
         uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd #v6.0.2
       -
         name: Download digests
-        uses: actions/download-artifact@37930b1c2abaa49bbe596cd826c3c89aef350131 #v7.0.0
+        uses: actions/download-artifact@70fc10c6e5e1ce46ad2ea6f2b72d43f7d47b13c3 #v8.0.0
         with:
           path: /tmp/digests
           pattern: digests-*