Update slsa generator action (1.5 -> 1.6)

Author: cowtowncoder

.github/workflows/release.yml

@@ -75,7 +75,7 @@ jobs:
       actions: read # To read the workflow path.
       id-token: write # To sign the provenance.
       contents: write # To add assets to a release.
-    uses: slsa-framework/slsa-github-generator/.github/workflows/generator_generic_slsa3.yml@v1.5.0
+    uses: slsa-framework/slsa-github-generator/.github/workflows/generator_generic_slsa3.yml@v1.6.0
     with:
       base64-subjects: "${{ needs.release.outputs.hash }}"
       provenance-name: "${{ needs.release.outputs.artifact_name }}.jar.intoto.jsonl"