Fix release dotnet install directory

Author: OwenMcGirr

.github/workflows/release.yml

@@ -23,6 +23,7 @@ jobs:
     runs-on: [self-hosted, windows, switchify-signing]
 
     env:
+      DOTNET_INSTALL_DIR: ${{ runner.temp }}\dotnet
       SWITCHIFY_SIGNING_MODE: certum-simplysign
       SWITCHIFY_CERTUM_CERT_THUMBPRINT: ${{ vars.CERTUM_CERT_THUMBPRINT }}
       SWITCHIFY_CERTUM_TIMESTAMP_URL: http://time.certum.pl