chore: Bump System.Collections.Immutable from 10.0.5 to 10.0.6

---
updated-dependencies:
- dependency-name: System.Collections.Immutable
  dependency-version: 10.0.6
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

src/Sharpy.Core/Sharpy.Core.csproj

@@ -18,7 +18,7 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="System.Collections.Immutable" Version="10.0.5" />
+    <PackageReference Include="System.Collections.Immutable" Version="10.0.6" />
     <!-- Polyfill for System.Index/Range on netstandard2.0 -->
     <PackageReference Include="Microsoft.Bcl.Memory" Version="10.0.5" Condition="'$(TargetFramework)' == 'netstandard2.0'" />
     <!-- Async interfaces for IAsyncEnumerable<T>, IAsyncDisposable (Phase 10 prep) -->