C#: Address review comments.

Author: michaelnebel

csharp/extractor/Semmle.Extraction.CSharp.DependencyFetching/DependencyManager.cs

@@ -33,7 +33,7 @@ public sealed class DependencyManager : IDisposable
 
 
         /// <summary>
-        /// Performs a C# dependency fetching.
+        /// Performs C# dependency fetching.
         /// </summary>
         /// <param name="options">Dependency fetching options</param>
         /// <param name="logger">Logger for dependency fetching progress.</param>

csharp/extractor/Semmle.Extraction.CSharp.DependencyFetching/DependencyOptions.cs

@@ -53,9 +53,7 @@ public interface IDependencyOptions
 
     public class DependencyOptions : IDependencyOptions
     {
-        private static readonly DependencyOptions instance = new DependencyOptions();
-
-        public static IDependencyOptions Default => instance;
+        public static IDependencyOptions Default => new DependencyOptions();
 
         public IList<string> DllDirs { get; set; } = new List<string>();
 

csharp/extractor/Semmle.Extraction.CSharp.DependencyFetching/Semmle.Extraction.CSharp.DependencyFetching.csproj

@@ -10,10 +10,10 @@
     <Nullable>enable</Nullable>
   </PropertyGroup>
 
-	<ItemGroup>
-		<ProjectReference Include="..\Semmle.Util\Semmle.Util.csproj" />
+  <ItemGroup>
+    <ProjectReference Include="..\Semmle.Util\Semmle.Util.csproj" />
     <ProjectReference Include="..\Semmle.Extraction\Semmle.Extraction.csproj" />
-	</ItemGroup>
+  </ItemGroup>
 
   <ItemGroup>
     <Folder Include="Properties\" />