workflows/ci.yml: bump Coq version to 8.16.1.

Author: chathhorn-galois

.github/workflows/ci.yml

@@ -514,9 +514,9 @@ jobs:
         with:
           ocaml-compiler: "4.14"
 
-      - run: opam repo add coq-released https://coq.inria.fr/opam/released
+      - run: opam repo add rocq-released https://rocq-prover.org/opam/released
 
-      - run: opam install -y coq=8.15.2 coq-bits=1.1.0
+      - run: opam install -y coq=8.16.1 coq-bits=1.1.0
 
       # FIXME: the following steps generate Coq libraries for the SAW core to
       # Coq translator and builds them; if we do other Coq tests, these steps