chore: cleanup unused usings 🧹 (open-feature#240)

## This PR

Cleanup 🧹 unused usings from the code base

Signed-off-by: Benjamin Evenson <[email protected]>

Author: benjiro

src/OpenFeature/IFeatureClient.cs

@@ -1,6 +1,5 @@
 using System.Collections.Generic;
 using System.Threading.Tasks;
-using OpenFeature.Constant;
 using OpenFeature.Model;
 
 namespace OpenFeature

src/OpenFeature/Model/BaseMetadata.cs

@@ -1,4 +1,3 @@
-using System;
 using System.Collections.Generic;
 using System.Collections.Immutable;
 

src/OpenFeature/Model/FlagMetadata.cs

@@ -1,6 +1,4 @@
-using System;
 using System.Collections.Generic;
-using System.Collections.Immutable;
 
 #nullable enable
 namespace OpenFeature.Model;

src/OpenFeature/Providers/Memory/InMemoryProvider.cs

@@ -1,6 +1,4 @@
-using System;
 using System.Collections.Generic;
-using System.Collections.Immutable;
 using System.Linq;
 using System.Threading.Tasks;
 using OpenFeature.Constant;

test/OpenFeature.E2ETests/Steps/EvaluationStepDefinitions.cs

@@ -1,8 +1,4 @@
-using System;
 using System.Collections.Generic;
-using System.Collections.Immutable;
-using System.ComponentModel.DataAnnotations;
-using System.Text.RegularExpressions;
 using System.Threading.Tasks;
 using OpenFeature.Constant;
 using OpenFeature.Extension;

test/OpenFeature.Tests/FlagMetadataTest.cs

@@ -1,4 +1,3 @@
-using System;
 using System.Collections.Generic;
 using OpenFeature.Model;
 using OpenFeature.Tests.Internal;

test/OpenFeature.Tests/TestUtils.cs

@@ -1,6 +1,5 @@
 using System;
 using System.Collections.Generic;
-using System.Diagnostics;
 using System.Threading;
 using System.Threading.Tasks;