Improve cache implementation for concurrent access · SchematicHQ/schematic-csharp@5fc7a05

ubuntu-latest pipelines will use ubuntu-24.04 soon. For more details, see https://github.com/actions/runner-images/issues/10636

Run Tests: src/SchematicHQ.Client/SchematicApi.cs#L19

Possible null reference argument for parameter 'value' in 'void Dictionary<string, string>.Add(string key, string value)'.

Run Tests: src/SchematicHQ.Client/Core/Public/ClientOptionsCustom.cs#L10

Non-nullable property 'FlagDefaults' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the property as nullable.

Run Tests: src/SchematicHQ.Client/Core/Public/ClientOptionsCustom.cs#L11

Non-nullable property 'Logger' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the property as nullable.

Run Tests: src/SchematicHQ.Client/Core/Public/ClientOptionsCustom.cs#L12

Non-nullable property 'CacheProviders' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the property as nullable.

Run Tests: src/SchematicHQ.Client/Accounts/AccountsClient.cs#L38