aesGcmDecryptBytes(): Promise<Uint8Array>
AES-GCM decrypt with raw key bytes. The mirror of aesGcmEncryptBytes; note it measures the ciphertext, which carries the tag the plaintext does not.
Anything too short to hold a tag never came from this format, so it is rejected by name rather than left to fail as a bad tag — reading a tag out of it would take bytes from the wrong end of the value.
Promise<Uint8Array>