Resolve dotnet format warnings

Author: chris-codeflow

src/GitVersion.Core.Tests/VersionCalculation/SemanticVersionTests.cs

@@ -81,10 +81,7 @@ public void VersionSorting()
     public void ToStringWithInvalidFormatTest()
     {
         var semVer = BuildSemVer(1, 2, 3, "rc", 1, 1);
-        Should.Throw<FormatException>(() => 
-        {
-            semVer.ToString("invalid");
-        });
+        Should.Throw<FormatException>(() => semVer.ToString("invalid"));
     }
 
     [TestCase(1, 2, 3, null, null, null, null, null, null, ExpectedResult = "1.2.3")]

src/GitVersion.Core/VersionCalculation/SemanticVersioning/SemanticVersionPreReleaseTag.cs

@@ -141,7 +141,7 @@ public string ToString(string format, IFormatProvider formatProvider)
 
         return format switch
         {
-            "t" => (Number.HasValue ? Name.IsNullOrEmpty() ? $"{Number}" : $"{Name}.{Number}" : Name),
+            "t" => (Number.HasValue ? Name.IsNullOrEmpty() ? $"{Number}" : $"{Name}.{Number}" : Name!),
             "l" => (Number.HasValue ? FormatLegacy(GetLegacyName(), Number.Value.ToString()) : FormatLegacy(GetLegacyName())),
             _ => throw new FormatException($"Unknown format '{format}'.")
         };