Update msgpack fork dependency (#35988) (#36043)

(cherry picked from commit 17939826efa20a97f087b3d390ec5136df350bae)

Co-authored-by: Mattermost Build <build@mattermost.com>

server/go.mod

@@ -257,5 +257,5 @@ replace github.com/ledongthuc/pdf => github.com/ledongthuc/pdf v0.0.0-2024020113
 // version always. Tablewriter has made breaking changes to its latest release.
 replace github.com/olekukonko/tablewriter => github.com/olekukonko/tablewriter v0.0.5
 
-// See MM-66167 for more details.
-replace github.com/vmihailenco/msgpack/v5 => github.com/mattermost/msgpack/v5 v5.0.0-20260120151306-2f9c67d7e57f
+// See MM-66167, MM-68222 for more details.
+replace github.com/vmihailenco/msgpack/v5 => github.com/mattermost/msgpack/v5 v5.0.0-20260408165622-cadfad56a815