Fix UI snapshots. (#3585)

* Remove old snapshots.

* Add a check for the correct simulator name.

* Record mismatched snapshots.

* Regenerate more snapshots using a (temporary) higher precision.

* Fix snapshot.

UITests/Sources/Application.swift

@@ -47,6 +47,9 @@ enum Application {
         guard deviceModel == requirediPhoneSimulator || deviceModel == requirediPadSimulator else {
             fatalError("Running on \(deviceModel) but we only support \(requirediPhoneSimulator) and \(requirediPadSimulator).")
         }
+        guard UIDevice.current.snapshotName == "iPhone-18.1" || UIDevice.current.snapshotName == "iPad-18.1" else {
+            fatalError("Running on a simulator that hasn't been renamed to match the expected snapshot filenames.")
+        }
     }
 }
 
@@ -91,15 +94,7 @@ extension XCUIApplication {
     }
 
     private var deviceName: String {
-        var name = UIDevice.current.name
-
-        // When running with parallel execution simulators are named "Clone 2 of iPhone 14" etc.
-        // Tidy this prefix out of the name to generate snapshots with the correct name.
-        if name.starts(with: "Clone "), let range = name.range(of: " of ") {
-            name = String(name[range.upperBound...])
-        }
-
-        return name
+        UIDevice.current.snapshotName
     }
 
     private var localeCode: String {
@@ -118,6 +113,20 @@ extension XCUIApplication {
     }
 }
 
+private extension UIDevice {
+    var snapshotName: String {
+        var name = name
+
+        // When running with parallel execution simulators are named "Clone 2 of iPhone 14" etc.
+        // Tidy this prefix out of the name to generate snapshots with the correct name.
+        if name.starts(with: "Clone "), let range = name.range(of: " of ") {
+            name = String(name[range.upperBound...])
+        }
+
+        return name
+    }
+}
+
 private extension UIImage {
     /// Adjusts the image by cropping it with the given edge insets.
     func inset(by insets: UIEdgeInsets) -> UIImage {