crypto/mlkem: swap order of return values of Encapsulate
Per FIPS 203 (https://csrc.nist.gov/pubs/fips/203/final), the order of return values should be sharedKey, ciphertext. This commit simply swaps those return values and updates any consumers of the Encapsulate() method to respect the new order.
Fixes #70950
Change-Id: I2a0d605e3baf7fe69510d60d3d35bbac18f883c9
Reviewed-on: https://go-review.googlesource.com/c/go/+/638376
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Austin Clements <austin@google.com>
Auto-Submit: Ian Lance Taylor <iant@golang.org> Reviewed-by: Filippo Valsorda <filippo@golang.org> Reviewed-by: Cherry Mui <cherryyz@google.com>