fix(deps): rollback to System.Collections.Immutable 8.x (#457)

* rollback to System.Collections.Immutable 8.x

* linting

---------

Co-authored-by: KyleMit <[email protected]>

Author: dancormier

.github/dependabot.yml

@@ -8,3 +8,6 @@ updates:
       directory: "/dotnet/"
       schedule:
           interval: "weekly"
+      ignore:
+          - dependency-name: "System.Collections.Immutable"
+            update-types: ["version-update:semver-major"]

dotnet/src/StackExchange.StacksIcons.csproj

@@ -41,6 +41,6 @@
 
 	<ItemGroup>
 		<FrameworkReference Include="Microsoft.AspNetCore.App" />
-		<PackageReference Include="System.Collections.Immutable" Version="9.0.10" />
+		<PackageReference Include="System.Collections.Immutable" Version="8.0.0" />
 	</ItemGroup>
 </Project>