ci(wheels): Use homebrew to install libpng on MacOS ARM runners

Until we can figure out a better solution, having homebrew install libpng will work around the issue with Wheels checks failing due to trying to link the too-old version of PNG installed to the macos-14 gh runners

Signed-off-by: Zach Lewis <zachcanbereached@gmail.com>

.github/workflows/wheel.yml

@@ -331,6 +331,7 @@ jobs:
         env:
           CIBW_BUILD: ${{ matrix.python }}
           CIBW_ARCHS: ${{ matrix.arch }}
+          CIBW_BEFORE_ALL: "brew install libpng"
 
       - uses: actions/upload-artifact@v4
         with: