[ci] Fix Windows checksumming

.github/workflows/ci.yaml

@@ -174,6 +174,7 @@ jobs:
           name=cargo-deny
           tag=$(git describe --tags --abbrev=0)
           release_name="$name-$tag-${{ matrix.target }}"
+          release_tar="${release_name}.tar.gz"
           mkdir "$release_name"
 
           if [ "${{ matrix.target }}" != "x86_64-pc-windows-msvc" ]; then
@@ -182,11 +183,17 @@ jobs:
 
           cp "target/${{ matrix.target }}/release/${{ matrix.bin }}" "$release_name/"
           cp README.md LICENSE-APACHE LICENSE-MIT "$release_name/"
-          tar czvf "$release_name.tar.gz" "$release_name"
+          tar czvf "$release_tar" "$release_name"
 
           rm -r "$release_name"
 
-          echo -n "$(shasum -ba 256 "$release_name.tar.gz" | cut -d " " -f 1)" > "$release_name.tar.gz.sha256"
+          # Windows environments in github actions don't have the gnu coreutils installed,
+          # which includes the shasum exe, so we just use powershell instead
+          if [ "{{ matrix.os }}" == "windows-latest" ]; then
+            echo "(Get-FileHash \"${release_tar}\" -Algorithm SHA256).Hash | Out-File -Encoding ASCII -NoNewline \"${release_tar}.sha256\"" | pwsh -c -
+          else
+            echo -n "$(shasum -ba 256 "${release_tar}" | cut -d " " -f 1)" > "${release_tar}.sha256"
+          fi
       - name: Publish
         uses: softprops/action-gh-release@v1
         with: