changed fcntl to portalocker to ensure compatiblity with windows

[poorvigupta26]

resolve for #44

[CLAassistant]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.
_{You have signed the CLA already but the status is still pending? Let us recheck it.}

[muellerberndt]

Thanks! I believe we need to update requirements.txt also?

[muellerberndt]

Please also run ruff check . --fix once in the root so we get rid of those linter errors :)

[poorvigupta26]

Thanks! I believe we need to update requirements.txt also?

thanks for pointing that out. have made the necessary changes now :)