Use version `4.5` of the `Microsoft.CodeAnalysis.CSharp` package.

Directory.Packages.props

@@ -65,7 +65,7 @@
     <PackageVersion Include="Microsoft.AspNetCore.TestHost" Version="8.0.0" />
     <PackageVersion Include="Microsoft.AspNetCore.WebUtilities" Version="8.0.0" />
     <PackageVersion Include="Microsoft.Bcl.AsyncInterfaces" Version="8.0.0" />
-    <PackageVersion Include="Microsoft.CodeAnalysis.CSharp" Version="4.7.0" />
+    <PackageVersion Include="Microsoft.CodeAnalysis.CSharp" Version="4.5.0" />
     <PackageVersion Include="Microsoft.CSharp" Version="4.7.0" />
     <PackageVersion Include="Microsoft.Data.Sqlite" Version="8.0.0" />
     <PackageVersion Include="Microsoft.EntityFrameworkCore" Version="8.0.0" />