lib_context: update to irmin.3.2.0
This MR upgrades lib_context
to use the Irmin 3.2.0. The corresponding opam-repository
MR is opam-repository!260 (merged).
Irmin.3.2.0 release is necessary for improving the memory usage during snapshot import/export (see #2312 (closed)), which is done in a following MR (!4862 (merged)).
It also exposes better errors for verify_proof
functions (see #2645 (closed)), and explicitly forbids adding empty trees to the storage.
Edited by Victor Allombert