feat: add visionOS support (#2190)

This PR adds support for visionOS. I've migrated the `UIScreen` API to take `displayScale` from `currentTraitCollection` - same as I did in Core (https://github.com/facebook/react-native/pull/41214/files)

RNSVG.podspec

@@ -19,7 +19,7 @@ Pod::Spec.new do |s|
   s.requires_arc    = true
 
   if fabric_enabled
-    s.platforms = { :osx => "10.14", ios: '12.4', tvos: '11.0' }
+    s.platforms = { :osx => "10.14", :ios => "12.4", :tvos => "11.0", :visionos => "1.0" }
     install_modules_dependencies(s)
 
     s.subspec "common" do |ss|
@@ -28,7 +28,7 @@ Pod::Spec.new do |s|
       ss.pod_target_xcconfig  = { "HEADER_SEARCH_PATHS" => "\"$(PODS_TARGET_SRCROOT)/common/cpp\"" }
     end
   else
-    s.platforms         = { :osx => "10.14", :ios => "10.0", :tvos => "9.2" }
+    s.platforms         = { :osx => "10.14", :ios => "10.0", :tvos => "9.2", :visionos => "1.0" }
     s.exclude_files      = 'apple/Utils/RNSVGFabricConversions.h'
     s.dependency           'React-Core'
   end

apple/RNSVGRenderable.mm

@@ -245,10 +245,17 @@ - (void)renderTo:(CGContextRef)context rect:(CGRect)rect
     CGSize boundsSize = bounds.size;
     CGFloat height = boundsSize.height;
     CGFloat width = boundsSize.width;
+    CGFloat scale = 0.0;
 #if TARGET_OS_OSX
-    CGFloat scale = [[NSScreen mainScreen] backingScaleFactor];
+    scale = [[NSScreen mainScreen] backingScaleFactor];
 #else
-    CGFloat scale = [[UIScreen mainScreen] scale];
+    if (@available(iOS 13.0, *)) {
+      scale = [UITraitCollection currentTraitCollection].displayScale;
+    } else {
+#if !TARGET_OS_VISION
+      scale = [[UIScreen mainScreen] scale];
+#endif
+    }
 #endif // TARGET_OS_OSX
     NSUInteger iheight = (NSUInteger)height;
     NSUInteger iwidth = (NSUInteger)width;