(maint) Update dependency JetBrains.Annotations to v2025

Author: renovate[bot]

src/Diagramming/Diagramming.csproj

@@ -38,7 +38,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="JetBrains.Annotations" Version="2024.3.0" PrivateAssets="all" />
+    <PackageReference Include="JetBrains.Annotations" Version="2025.2.1" PrivateAssets="all" />
     <PackageReference Include="Statiq.Common" Version="1.0.0-beta.65" />
     <PackageReference Include="Statiq.Core" Version="1.0.0-beta.65" />
     <PackageReference Include="Microsoft.SourceLink.GitHub" Version="8.0.0">