Update jetbrains to v2026

Author: renovate[bot]

Directory.Packages.props

@@ -21,7 +21,7 @@
     <GlobalPackageReference Include="JetBrains.ExternalAnnotations" Version="10.2.169" />
   </ItemGroup>
   <ItemGroup>
-    <PackageVersion Include="JetBrains.Annotations.Sources" Version="2025.2.4" />
+    <PackageVersion Include="JetBrains.Annotations.Sources" Version="2026.2.0" />
     <PackageVersion Include="JetBrains.dotCover.CommandLineTools" Version="2026.1.3" />
     <PackageVersion Include="JetBrains.ReSharper.GlobalTools" Version="2026.1.3" />
     <PackageVersion Include="Microsoft.CodeAnalysis.CSharp" Version="5.3.0" />