fix: Change encoding to UTF-8 for opening README.md in setup.py

[ChoYongchae]

Thanks for nice repository!

This commit adjusts the encoding to UTF-8 for the 'open' command used to access the README.md file in the setup.py. The modification aims to ensure compatibility with the default language settings in Windows environments.

Regards, Choyongchae

[ChoYongchae]

Reference (before fix):

• Environment: Windows, Korean language setting
• Error message:

  error: subprocess-exited-with-error

  × python setup.py egg_info did not run successfully.
  │ exit code: 1
  ╰─> [6 lines of output]
      Traceback (most recent call last):
        File "<string>", line 2, in <module>
        File "<pip-setuptools-caller>", line 34, in <module>
        File "D:\ImageBind\setup.py", line 11, in <module>
          long_description=open('README.md').read(),
      UnicodeDecodeError: 'cp949' codec can't decode byte 0xe2 in position 952: illegal multibyte sequence
      [end of output]

  note: This error originates from a subprocess, and is likely not a problem with pip.
error: metadata-generation-failed

× Encountered error while generating package metadata.
╰─> See above for output.```

[ChrisjanWust]

Thanks for squashing this little bug, Choyongchae. Merging now 👍