Add some minor improvements

src/NerdBank.GitVersioning/ManagedGit/GitAnnotatedTagReader.cs

@@ -59,7 +59,7 @@ public static GitAnnotatedTag Read(Stream stream, GitObjectId sha)
     /// A <see cref="ReadOnlySpan{T}"/> which contains the <see cref="GitAnnotatedTag"/> in its text representation.
     /// </param>
     /// <param name="sha">
-    /// The <see cref="GitObjectId"/> of the commit.
+    /// The <see cref="GitObjectId"/> of the annotated tag.
     /// </param>
     /// <returns>
     /// The <see cref="GitAnnotatedTag"/>.

src/NerdBank.GitVersioning/ManagedGit/GitRepository.cs

@@ -804,13 +804,12 @@ private ReadOnlyMemory<GitPack> LoadPacks()
     /// </summary>
     private IEnumerable<string> EnumeratePackedRefsEntries()
     {
-        // Match in packed-refs file.
         string packedRefPath = Path.Combine(this.CommonDirectory, "packed-refs");
         if (File.Exists(packedRefPath))
         {
-            using StreamReader? refReader = File.OpenText(packedRefPath);
+            using StreamReader refReader = File.OpenText(packedRefPath);
             string? line;
-            while ((line = refReader.ReadLine()) is object)
+            while ((line = refReader.ReadLine()) is not null)
             {
                 if (line.StartsWith("#", StringComparison.Ordinal))
                 {