Boot Camp error "Windows cannot locate the disk and partition"
You do not have an EFI partition. You output from diskutil list should look something like below. Here disk0s1 is the EFI partition. This is missing in your output.
/dev/disk0 (internal, physical):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *273.7 GB   disk0
   1:                        EFI ⁨EFI⁩                     209.7 MB   disk0s1
   2:                 Apple_APFS ⁨Container disk1⁩         273.4 GB   disk0s2

/dev/disk1 (synthesized):
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      APFS Container Scheme -                      +273.4 GB   disk1
                                 Physical Store disk0s2
   1:                APFS Volume ⁨MyBigSur - Data⁩         8.4 GB     disk1s1
   2:                APFS Volume ⁨Preboot⁩                 292.2 MB   disk1s2
   3:                APFS Volume ⁨Recovery⁩                613.6 MB   disk1s3
   4:                APFS Volume ⁨VM⁩                      1.1 MB     disk1s4
   5:                APFS Volume ⁨MyBigSur⁩                15.0 GB    disk1s5
   6:              APFS Snapshot ⁨com.apple.os.update-...⁩ 15.0 GB    disk1s5s1

There is a good chance the EFI partition was deleted and can be recreated. You would first need to post the output from the following command.
diskutil info disk0s1 | grep -e Offset -e Size