feat: add repository-scoped cache token for action binaries

Add a new optional cache-token input to both published actions.

- Default cache key token is now action_repository + release_tag.
- Cache key uses this token plus runner architecture.
- prepare-release workflow passes github.sha as a fixed token.

This prevents cross-repository cache collisions when consumers pull
vociferate binaries produced by this repository.

.gitea/workflows/prepare-release.yml

@@ -44,6 +44,7 @@ jobs:
         with:
           version: ${{ inputs.version }}
           token: ${{ secrets.GITHUB_TOKEN }}
+          cache-token: ${{ github.sha }}
 
       - name: Summarize prepared release
         run: |