Update anchore/sbom-action action to v0.17.8 (nginx#2804)

| datasource  | package             | from    | to      |
| ----------- | ------------------- | ------- | ------- |
| github-tags | anchore/sbom-action | v0.17.7 | v0.17.8 |

Signed-off-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>
Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

.github/workflows/ci.yml

@@ -161,7 +161,7 @@ jobs:
         if: ${{ github.event_name == 'push' && github.ref != 'refs/heads/main' }}
 
       - name: Download Syft
-        uses: anchore/sbom-action/download-syft@fc46e51fd3cb168ffb36c6d1915723c47db58abb # v0.17.7
+        uses: anchore/sbom-action/download-syft@55dc4ee22412511ee8c3142cbea40418e6cec693 # v0.17.8
         if: github.ref_type == 'tag'
 
       - name: Install Cosign