Compound - Swift 6.2 and Main actor isolation (#5109)

* compound is now using 6.2 and main actor isolation + some tweaks to make it build tests and EX

* better handling of the nonisolated context for CompoundUIColors

* improving docs

* fix comment

* remove unused Sendable conformance

compound-ios/Package.swift

@@ -1,4 +1,4 @@
-// swift-tools-version: 5.9
+// swift-tools-version: 6.2
 
 import PackageDescription
 
@@ -22,6 +22,9 @@ let package = Package(
                 .product(name: "CompoundDesignTokens", package: "compound-design-tokens"),
                 .product(name: "SwiftUIIntrospect", package: "SwiftUI-Introspect"),
                 .product(name: "SFSafeSymbols", package: "SFSafeSymbols")
+            ],
+            swiftSettings: [
+                .defaultIsolation(MainActor.self)
             ]
         ),
         .testTarget(