[Bug] `ioutil` is deprecated

[vaguecoder]

Describe the Bug

ioutil is deprecated. Replace all occurrences of ioutil with io or os w.r.t. the functions in use.

To Reproduce

NA

Additional Context

NA

Ownership of Contribution

If the triage is approved,

• I wish to submit the PR myself.
• I wish to submit the PR. But if someone is willing to do it, go ahead.
• I don't know how to fix this or make these changes. I wish others to pick this up for me.

[tanryberdi]

@assign