ci: added sigstore installer to workflow (#79)

Author: MadsRC

.github/workflows/release.yaml

@@ -1,5 +1,5 @@
 concurrency:
-  group: ${{ github.workflow }}-${{ github.ref }}
+  group: "${{ github.workflow }}-${{ github.ref }}"
   cancel-in-progress: true
 
 on:
@@ -19,6 +19,7 @@ jobs:
       id-token: write
     runs-on: ubuntu-latest
     steps:
+    - uses: sigstore/cosign-installer@59acb6260d9c0ba8f4a2f9d9b48431a222b68e20 # v3
     - uses: actions/checkout@0ad4b8fadaa221de15dcec353f45205ec38ea70b # v4
       with:
         # Disabling shallow clone is recommended for improving relevancy of reporting