Reintroduce IsDirty boolean property from 2.3

With the change to ThisAssembly.Constants, we introduced a bug that caused IsDirty to be a string contant, instead of the boolean it was up to 2.3.

Closes #243

src/Analyzer/GitInfoGenerator.cs

@@ -0,0 +1,40 @@
+using Microsoft.CodeAnalysis;
+
+[Generator(LanguageNames.CSharp)]
+class GitInfoGenerator : IIncrementalGenerator
+{
+    public void Initialize(IncrementalGeneratorInitializationContext context)
+    {
+        context.RegisterSourceOutput(
+            context.AdditionalTextsProvider
+                .Combine(context.AnalyzerConfigOptionsProvider)
+                .Combine(context.ParseOptionsProvider)
+                .Collect(),
+            (c, _) =>
+            {
+                c.AddSource("ThisAssembly.Git.IsDirty.g",
+                    $$"""
+                    //------------------------------------------------------------------------------
+                    // <auto-generated>
+                    //     This code was generated by a tool.
+                    //
+                    //     GitInfo: {{ThisAssembly.Info.InformationalVersion}}
+                    //
+                    //     Changes to this file may cause incorrect behavior and will be lost if
+                    //     the code is regenerated.
+                    // </auto-generated>
+                    //------------------------------------------------------------------------------
+                    partial class ThisAssembly
+                    {
+                        partial class Git
+                        {
+                            /// <summary>
+                            /// Gets whether the current repository is dirty.
+                            /// </summary>
+                            public static bool IsDirty => bool.TryParse(IsDirtyString, out var dirty) && dirty;
+                        }
+                    }
+                    """);
+            });
+    }
+}

src/GitInfo/build/GitInfo.ThisAssembly.targets

@@ -37,7 +37,6 @@
 			    BeforeTargets="PrepareConstants" Condition="'$(GitThisAssembly)' == 'true'">
 
     <ItemGroup>
-      <Constant Include="IsDirty" Value="$(IsDirty)" Root="Git" />
       <Constant Include="IsDirtyString" Value="$(IsDirtyString)" Root="Git" />
       <Constant Include="RepositoryUrl" Value="$(GitRepositoryUrl)" Root="Git" />