Bump System.Collections.Immutable from 1.3.0 to 5.0.0 (#84)

Bumps [System.Collections.Immutable](https://github.com/dotnet/runtime) from 1.3.0 to 5.0.0.
- [Release notes](https://github.com/dotnet/runtime/releases)
- [Commits](https://github.com/dotnet/runtime/commits)

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

Co-authored-by: dependabot-preview[bot] <27856297+dependabot-preview[bot]@users.noreply.github.com>

Author: dependabot-preview[bot]

src/StructLinq.BCL/StructLinq.BCL.csproj

@@ -22,7 +22,7 @@
     <PackageReference Include="InlineIL.Fody" Version="1.6.0">
       <PrivateAssets>all</PrivateAssets>
     </PackageReference>
-    <PackageReference Include="System.Collections.Immutable" Version="1.3.0" />
+    <PackageReference Include="System.Collections.Immutable" Version="5.0.0" />
   </ItemGroup>
 
 </Project>