build_usd.py: Fix macOS build issues from bump to libpng v1.6.47

- Removed unnecessary patch for universal binary builds. This change
  was applied upstream in v1.6.40 in pnggroup/libpng@cd0ea2a.

- Explicitly disable framework builds to avoid issues with
  OpenImageIO. This was enabled in v1.6.41 in pnggroup/libpng@8fc13a8.

- Updated URL to point to pnggroup/libpng repository instead of
  depending on redirect.

For reference, build_usd.py was updated from v1.6.38 to v1.6.47
in change 2359710.

(Internal change: 2362090)

Author: sunyab

build_scripts/build_usd.py

@@ -1216,20 +1216,20 @@ def InstallTIFF(context, force, buildArgs):
 ############################################################
 # PNG
 
-PNG_URL = "https://github.com/glennrp/libpng/archive/refs/tags/v1.6.47.zip"
+PNG_URL = "https://github.com/pnggroup/libpng/archive/refs/tags/v1.6.47.zip"
 
 def InstallPNG(context, force, buildArgs):
     with CurrentWorkingDirectory(DownloadURL(PNG_URL, context, force)):
-        macArgs = []
+        # Framework builds were enabled by default in v1.6.41 in commit
+        # 8fc13a8. We explicitly disable this to maintain legacy behavior
+        # from v1.6.38, which is what this script used previously.
+        # OpenImageIO v2.5.16.0 runs into linker issues otherwise.
+        macArgs = ["-DPNG_FRAMEWORK=OFF"]]
+
         if MacOS() and apple_utils.IsTargetArm(context):
             # Ensure libpng's build doesn't erroneously activate inappropriate
             # Neon extensions
-            macArgs = ["-DCMAKE_C_FLAGS=\"-DPNG_ARM_NEON_OPT=0\""]
-
-            if context.targetUniversal:
-                PatchFile("scripts/genout.cmake.in",
-                [("CMAKE_OSX_ARCHITECTURES",
-                  "CMAKE_OSX_INTERNAL_ARCHITECTURES")])
+            macArgs += ["-DCMAKE_C_FLAGS=\"-DPNG_ARM_NEON_OPT=0\""]
 
         RunCMake(context, force, buildArgs + macArgs)