Fix warnings

Author: patriksvensson

src/Spectre.IO/Environment.cs

@@ -59,11 +59,6 @@ public Environment(IPlatform platform)
         return SystemEnv.GetEnvironmentVariable(variable);
     }
 
-    public DirectoryPath GetSpecialPath(KnownPath path)
-    {
-        throw new NotImplementedException();
-    }
-
     public DirectoryPath GetKnownPath(KnownPath path)
     {
         return KnownPathUtilities.GetFolderPath(Platform, path);
@@ -108,5 +103,4 @@ public DirectoryPath GetTempDirectory()
         var path = System.IO.Path.GetTempPath();
         return new DirectoryPath(path);
     }
-}
-
+}

src/Spectre.IO/Internal/Native.cs

@@ -8,7 +8,9 @@ internal static partial class Native
     public static class Unix
     {
         [DllImport("libc", SetLastError = true)]
+#pragma warning disable SA1300
         public static extern IntPtr getenv([MarshalAs(UnmanagedType.LPStr)] string name);
+#pragma warning restore SA1300
 
         public static string? GetFolder(KnownPath folder)
         {