Delete Linux MINT

Before you do anything make sure to have a good backup of macOS. Modifying partitions is dangerous and you could lose access to the data within macOS or damage macOS so it will no longer boot normally.

Is Linux Mint installed to the internal boot drive alongside macOS? If so, then you need to delete the Linux folder on the hidden EFI/ESP partition which contains the Linux bootloader. I haven't used Linux Mint much so I'm not sure of the exact details, but most Linux distributions will store the bootloader into a folder on the hidden EFI/ESP partition which also contains an folder called "EFI". Within this "EFI" folder you should see one named "apple" which you should not touch. Any other folder should be safe to delete. You may see a folder called "mint", "linuxmint", "ubuntu", or possibly even "boot". These Linux folders are safe to remove. This will prevent you from seeing the Linux GRUB bootloader if it is configured as the default Startup Item and prevent Linux being an option on the Option Boot menu.

You can delete the Linux bootloader folder while booted into Linux or from within macOS. You need to mount the hidden EFI/ESP partition which should be the first partition on the physical drive. Within Linux that should be labeled "/dev/sda1" and within macOS it should be "/dev/disk0s1".

To reabsorb the Linux partitions into the main Apple partition and/or Container you will need to delete each of the Linux partitions using Disk Utility. After deleting the partitions, then you need to try to merge them back into the main Apple partition or hidden Container (depends on your version of macOS). Partitions must be physically adjacent to one another in order to be merged together. It may take some trial and error to figure out which ones are physically adjacent to one another.

See the response here: Linux - Apple Community