Enable deterministic builds.

Use instructions from https://github.com/clairernovotny/DeterministicBuilds.

Author: bgrainger

src/Directory.Build.props

@@ -21,6 +21,11 @@
     <NoWarn>$(NoWarn);1591;NU5105</NoWarn>
   </PropertyGroup>
 
+  <PropertyGroup Condition=" '$(GITHUB_ACTIONS)' == 'true' OR '$(APPVEYOR)' == 'True' OR '$(TF_BUILD)' == 'True' ">
+    <ContinuousIntegrationBuild>true</ContinuousIntegrationBuild>
+    <Deterministic>true</Deterministic>
+  </PropertyGroup>
+
   <ItemGroup>
     <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.0.0" PrivateAssets="All"/>
   </ItemGroup>

src/Directory.Build.targets

@@ -0,0 +1,8 @@
+<Project>
+  <PropertyGroup>
+    <TargetFrameworkMonikerAssemblyAttributesPath>$([System.IO.Path]::Combine('$(IntermediateOutputPath)','$(TargetFrameworkMoniker).AssemblyAttributes$(DefaultLanguageSourceExtension)'))</TargetFrameworkMonikerAssemblyAttributesPath>
+  </PropertyGroup>
+  <ItemGroup>
+    <EmbeddedFiles Include="$(GeneratedAssemblyInfoFile)"/>
+  </ItemGroup>
+</Project>