fix: add public imports for InternalImportsByDefault compatibility

Update URL+IRI.swift to use public imports for Foundation and RFC_3987
to satisfy Swift 6's InternalImportsByDefault requirements.

Author: coenttb

Sources/RFC 3987 Foundation/URL+IRI.swift

@@ -1,5 +1,5 @@
-import Foundation
-import RFC_3987
+public import Foundation
+public import RFC_3987
 
 extension URL {
     /// Errors that can occur during IRI to URL conversion