Don't fail if dir already exists

.github/workflows/nugetTests.yml

@@ -30,7 +30,9 @@ jobs:
         with:
           ref: ${{ github.event.pull_request.head.sha }}
 
-      # Ubuntu agents require Mono to run nuget.exe, and to set permissions for the dotnet home directory
+      # Ubuntu agents require Mono to run nuget.exe.
+      # Also, there is an issue with the .NET setup action that requires setting permissions for the dotnet home directory.
+      # Therefore, we manually set permissions until the issue is resolved. (https://github.com/actions/setup-dotnet/issues/565)
       - name: Prepare Ubuntu agent
         if: matrix.os == 'ubuntu'
         run: |
@@ -42,7 +44,7 @@ jobs:
           sudo apt-get update
           sudo apt-get install -y mono-complete
           # Set permissions for the dotnet home directory
-          sudo mkdir /usr/share/dotnet
+          sudo mkdir -p /usr/share/dotnet
           sudo chmod 777 /usr/share/dotnet
 
       - name: Install .NET