Give linux a convenience init so tests can use it

Sources/Supabase/SupabaseClient.swift

@@ -128,7 +128,7 @@ public final class SupabaseClient: @unchecked Sendable {
   #endif
 
   #if os(Windows)
-    /// Create a new client.
+  /// Create a new client.
   /// - Parameters:
   ///   - supabaseURL: The unique Supabase URL which is supplied when you create a new project in
   /// your project dashboard.
@@ -148,6 +148,27 @@ public final class SupabaseClient: @unchecked Sendable {
   }
   #endif
 
+  #if os(Linux)
+  /// Create a new client.
+  /// - Parameters:
+  ///   - supabaseURL: The unique Supabase URL which is supplied when you create a new project in
+  /// your project dashboard.
+  ///   - supabaseKey: The unique Supabase Key which is supplied when you create a new project in
+  /// your project dashboard.
+  ///   - options: Custom options to configure client's behavior.
+  public convenience init(
+    supabaseURL: String,
+    supabaseKey: String,
+    options: SupabaseClientOptions
+  ) {
+    guard let supabaseURL = URL(string: supabaseURL) else {
+      fatalError("Invalid supabaseURL: \(supabaseURL)")
+    }
+
+    self.init(supabaseURL: supabaseURL, supabaseKey: supabaseKey, options: options)
+  }
+  #endif
+
   deinit {
     listenForAuthEventsTask.value?.cancel()
   }