Fix whitespace: Add final newlines to source files

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: paulirwin

src/Lucene.Net.TestFramework/Support/Util/SystemEnvironment.cs

@@ -124,4 +124,4 @@ public static void ReleaseCurrentDirectoryLock()
             currentDirectoryLock.Release();
         }
     }
-}
+}

src/Lucene.Net.Tests.Benchmark/ByTask/Utils/TestFileUtils.cs

@@ -178,4 +178,4 @@ public virtual void TestFullyDeleteEmptyDirectoryWithStringPath()
             assertFalse(Directory.Exists(tempDirPath));
         }
     }
-}
+}