ux: fix navigation placement in profile edit view

This PR fixes the issue with the placement of the back navigation button in the profile edit view for iOS 18 devices:

Changelog-Fixed: Fixed back nav button placement in profile edit view

Signed-off-by: ericholguin <ericholguin@apache.org>

damus/Views/Profile/EditMetadataView.swift

@@ -218,7 +218,7 @@ struct EditMetadataView: View {
         .background(Color(.systemGroupedBackground))
         .navigationBarBackButtonHidden()
         .toolbar {
-            ToolbarItem(placement: .principal) {
+            ToolbarItem(placement: .topBarLeading) {
                 navBackButton
             }
         }