Fix the release workflow

Author: AArnott

.github/workflows/release.yml

@@ -77,6 +77,8 @@ jobs:
     - name: 🔏 Code sign
       shell: pwsh
       run: >
+        rm global.json # avoid a need to install a particular SDK version
+
         dotnet tool install --tool-path obj SignClient
 
         obj/SignClient sign