Treat duplicate dependency warnings as errors (#38480)

* Treat duplicate dependency warnings as errors

* GitHub workflows

* commas

* Maybe we just don't use these?

* I think we can get rid of these?

.github/workflows/build-docfx.yml

@@ -27,7 +27,7 @@ jobs:
       run: dotnet restore
 
     - name: Build Project
-      run: dotnet build --no-restore /p:WarningsAsErrors=nullable
+      run: dotnet build --no-restore
 
     - name: Build DocFX
       uses: nikeee/docfx-action@v1.0.0

.github/workflows/build-map-renderer.yml

@@ -42,7 +42,7 @@ jobs:
         run: dotnet restore
 
       - name: Build Project
-        run: dotnet build Content.MapRenderer --configuration Release --no-restore /p:WarningsAsErrors=nullable /m
+        run: dotnet build Content.MapRenderer --configuration Release --no-restore /m
 
       - name: Run Map Renderer
         run: dotnet run --project Content.MapRenderer Dev

.github/workflows/build-test-debug.yml

@@ -42,7 +42,7 @@ jobs:
       run: dotnet restore
 
     - name: Build Project
-      run: dotnet build --configuration DebugOpt --no-restore /p:WarningsAsErrors=nullable /m
+      run: dotnet build --configuration DebugOpt --no-restore /m
 
     - name: Run Content.Tests
       run: dotnet test --no-build --configuration DebugOpt Content.Tests/Content.Tests.csproj -- NUnit.ConsoleOut=0