Update requirements.txt to solve cv2 import error ( libGL.so.1 )

[TarcisioOliveira2021]

When I tried to run iasam_app.py, I encountered the following error:

File "/inpaint-anything/iasam_app.py", line 17, in <module>
    import cv2
File "/opt/conda/envs/inpaint/lib/python3.10/site-packages/cv2/__init__.py", line 181, in <module>
    bootstrap()
File "/opt/conda/envs/inpaint/lib/python3.10/site-packages/cv2/__init__.py", line 153, in bootstrap
    native_module = importlib.import_module("cv2")
File "/opt/conda/envs/inpaint/lib/python3.10/importlib/__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
ImportError: libGL.so.1: cannot open shared object file: No such file or directory

After researching, I found a similar issue here: GitHub Issue #1270.

It seems like switching the OpenCV import to opencv-python-headless==4.8.1.78 is a good solution to avoid this error.