fix<ci>: use smaller release tag

.github/workflows/release.yml

@@ -31,14 +31,17 @@ jobs:
       - name: Build for Linux
         run: GOOS=linux GOARCH=amd64 go build -o sif-linux-amd64 ./cmd/sif
 
+      - name: Set release version
+        run: echo "RELEASE_VERSION=$(date +'%Y.%m.%d')" >> $GITHUB_ENV
+
       - name: Create Release
         id: create_release
         uses: actions/create-release@v1
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
         with:
-          tag_name: ${{ github.sha }}
-          release_name: Release ${{ github.sha }}
+          tag_name: v${{ env.RELEASE_VERSION }}
+          release_name: Release ${{ env.RELEASE_VERSION }}
           draft: false
           prerelease: false