-Wdeclaration-after-statement to .github/workflows/pq-all.yml.
rearrange code/gating in wolfcrypt/src/wc_mlkem.c:mlkemkey_encapsulate() for
clarity and to fix a -Wdeclaration-after-statement.
also, made mlkem_encapsulate_c() and mlkem_encapsulate() return error code
(currently always zero) rather than void, for consistency.
configure.ac: fix Kyber/ML-KEM option setup.