Bump JetBrains.Annotations from 2021.3.0 to 2023.3.0

Bumps [JetBrains.Annotations](https://github.com/JetBrains/JetBrains.Annotations) from 2021.3.0 to 2023.3.0.
- [Commits](JetBrains/JetBrains.Annotations@v2021.3.0...2023.3)

---
updated-dependencies:
- dependency-name: JetBrains.Annotations
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

src/X.Spectator/X.Spectator.csproj

@@ -21,7 +21,7 @@
     </PropertyGroup>
 
     <ItemGroup>
-      <PackageReference Include="JetBrains.Annotations" Version="2021.3.0" />
+      <PackageReference Include="JetBrains.Annotations" Version="2023.3.0" />
       <PackageReference Include="System.Collections.Immutable" Version="8.0.0" />
     </ItemGroup>