Update slsa-framework/slsa-github-generator action to v2.1.0 (#69)

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

Author: renovate[bot]

.github/workflows/releaser.yml

@@ -82,7 +82,7 @@ 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@v2.0.0
+    uses: slsa-framework/slsa-github-generator/.github/workflows/generator_generic_slsa3.yml@v2.1.0
     with:
       base64-subjects: "${{ needs.release.outputs.hashes }}"
       upload-assets: true # upload to a new release