Remove deprecated sgx_enclave macro
Remove deprecated sgx_enclave macro

The replacements have been available as cc_unsigned_enclave and
debug_sign_enclave with backends = sgx.backend_labels.

PiperOrigin-RevId: 284828515
Change-Id: I8ea9a54fc36e89a6770b89e6bdce403a4bd82fdd

google/asylo,google/asylo,google/asylo,google/asylo,google/asylo,google/asylo