Improve workflows: Add GitHub token support for Trivy scans

Enhancements:
- Add GITHUB_TOKEN environment variable to security and release workflows
- Enable better rate limits for Trivy vulnerability scanner
- Add continue-on-error for resilient security scans
- Add GitHub token availability check with helpful messages
- Update documentation with GitHub token setup instructions

 Security Benefits:
- Reduced API rate limiting issues
- More reliable vulnerability scanning
- Better error handling and user feedback
- Improved workflow stability

 Documentation:
- Added GitHub token setup guide in GITEA_WORKFLOWS.md
- Clear instructions for repository secret configuration

.gitea/workflows/release.yml

@@ -156,6 +156,8 @@ jobs:
         image-ref: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:${{ needs.create-release.outputs.version }}
         format: 'sarif'
         output: 'trivy-results.sarif'
+      env:
+        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
         
     - name: Upload Trivy scan results
       uses: actions/upload-artifact@v3