Modified the accessibility modifier of ProductVersionParser to internal + code cleanup

Author: t4m45

src/TestableIO.System.IO.Abstractions.TestingHelpers/MockFileVersionInfo.cs

@@ -1,5 +1,4 @@
 using System.Diagnostics;
-using System.Runtime.InteropServices;
 using System.Text;
 
 namespace System.IO.Abstractions.TestingHelpers

src/TestableIO.System.IO.Abstractions.TestingHelpers/ProductVersionParser.cs

@@ -6,7 +6,7 @@ namespace System.IO.Abstractions.TestingHelpers
     /// <summary>
     /// Provides functionality to parse a product version string into its major, minor, build, and private parts.
     /// </summary>
-    public static class ProductVersionParser
+    internal static class ProductVersionParser
     {
         /// <summary>
         /// Parses a product version string and extracts the numeric values for the major, minor, build, and private parts,

tests/TestableIO.System.IO.Abstractions.TestingHelpers.Tests/MockFileVersionInfoFactoryTests.cs

@@ -1,9 +1,5 @@
 using NUnit.Framework;
-using System;
 using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
 
 namespace System.IO.Abstractions.TestingHelpers.Tests
 {
@@ -39,7 +35,7 @@ public void MockFileVersionInfoFactory_GetVersionInfo_ShouldThrowFileNotFoundExc
 
             // Act
             TestDelegate code = () => fileSystem.FileVersionInfo.GetVersionInfo(@"c:\foo.txt");
-            
+
             // Assert
             Assert.Throws<FileNotFoundException>(code);
         }

tests/TestableIO.System.IO.Abstractions.TestingHelpers.Tests/MockFileVersionInfoTests.cs

@@ -1,5 +1,4 @@
 using NUnit.Framework;
-using System.Collections;
 
 namespace System.IO.Abstractions.TestingHelpers.Tests
 {