Hi Zian,
Depending on what you are sharing, certain files will be automatically deleted. For example, if you are sharing packages, they are staged in the folder and deleted after the package is uploaded. (You can see this happening if you navigate to the folder while publishing is in progress.)
The files that would be automatically deleted already have been after sharing has been completed. The remaining files in your SharingProcesses folder can be removed manually. The recommended workflow is to clear the Job Queue from ArcGIS Pro. See this: Sharing job status. Clicking Remove Finished Jobs will delete the files and job folders in your SharingProcesses folder.
Hope it helps.
Cheers,
Jonah