github: Rename the macos-toolchain artifact to macos-ucrt-toolchain

.github/workflows/build.yml

@@ -192,7 +192,7 @@ jobs:
           tar -Jcf ../$NAME.tar.xz $NAME
       - uses: actions/upload-artifact@v3
         with:
-          name: macos-toolchain
+          name: macos-ucrt-toolchain
           path: |
             llvm-mingw-*.tar.xz
           retention-days: 7