Treat warnings as errors during CI tests

for some reason a *missing dependency dll* is treated as a *warning*???

Author: drewcassidy

tests/plugin-mod-legacy/PluginModLegacy/plugin-mod-legacy.csproj

@@ -13,6 +13,7 @@
     <TargetFrameworkProfile />
     <NuGetPackageImportStamp>
     </NuGetPackageImportStamp>
+    <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
     <DebugSymbols>true</DebugSymbols>

tests/plugin-mod-nuget/plugin-mod-nuget.csproj

@@ -4,6 +4,7 @@
   <PropertyGroup>
     <KSPBuildToolsVersion Condition = " '$(KSPBuildToolsVersion)' == ''">*-*</KSPBuildToolsVersion>
     <RootNamespace>plugin-mod</RootNamespace>
+    <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
   </PropertyGroup>
 
   <ItemGroup>

tests/plugin-mod/plugin-mod.csproj

@@ -22,6 +22,7 @@
     <AssemblyCopyright>2024 KSPModdingLibs Contributors</AssemblyCopyright>
     <AssemblyName>PluginMod</AssemblyName>
     <KSPBT_ModRoot>$(MSBuildThisFileDirectory)/GameData/$(MSBuildProjectName)</KSPBT_ModRoot>
+    <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
   </PropertyGroup>
 
   <!-- DLL Dependencies-->