@Ashish Darji, Thanks for posting in Q&A. Based on my researching, I didn't find there's no such setting in Intune can disable WiFi sharing via QR code. Then I go to check in Android MDM and find there's no such setting can control "WiFi sharing via QR code". You can feedback to Google to request the feature.
https://developers.google.com/android/work/requirements
Note: Non-Microsoft link, just for the reference.
For your situation, you can change your WiFI authentication to certificate authentication to avoid sharing.
Hope the above information can help.
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