unstructured

e3417d7e - fix: Fix for Pillow error when extracting PNG images (#3998)

fix: Fix for Pillow error when extracting PNG images (#3998) When I tried to partition a PNG file and extract images, I got an error from Pillow: ``` WARNING unstructured:pdf_image_utils.py:230 Image Extraction Error: Skipping the failed image Traceback (most recent call last): File "/Users/austin/.pyenv/versions/unstructured/lib/python3.10/site-packages/PIL/JpegImagePlugin.py", line 666, in _save rawmode = RAWMODE[im.mode] KeyError: 'RGBA' ``` The issue is that a PNG has an additional layer that cannot be saved off in jpeg format. We can fix this with a quick conversion. I added a png test case that is now passing with this fix.