[opam] update version number and dependencies

opam/opam

 opam-version: "2.0"
 name: "frama-c"
 synopsis: "Platform dedicated to the analysis of source code written in C"
-version: "23.1"
+version: "24.0-beta"
 description:"""
 Frama-C gathers several analysis techniques in a single collaborative
 framework, based on analyzers (called "plug-ins") that can build upon the
@@ -65,10 +65,10 @@ authors: [
   "Kostyantyn Vorobyov"
   "Boris Yakobowski"
 ]
-homepage: "http://frama-c.com/"
+homepage: "https://frama-c.com/"
 license: "LGPL-2.1-only"
 dev-repo: "git+https://git.frama-c.com/pub/frama-c.git"
-doc: "http://frama-c.com/download/user-manual-23.0-Vanadium.pdf"
+doc: "http://frama-c.com/download/user-manual-24.0-beta-Chromium.pdf"
 bug-reports: "https://git.frama-c.com/pub/frama-c/issues"
 tags: [
   "deductive"
@@ -117,7 +117,7 @@ depends: [
   ( "alt-ergo-free" | "alt-ergo" )
   "conf-graphviz" { post }
   "conf-time" { with-test }
-  "ocaml" { >= "4.08.1" & < "4.13.0" }
+  "ocaml" { >= "4.08.1" }
   "ocamlfind" # needed beyond build stage, used by -load-module
   "ocamlgraph" { >= "1.8.8" }
   "why3" { >= "1.4.0" & < "1.5~" }
@@ -140,7 +140,7 @@ depopts: [
 messages: [
   "The Frama-C/Wp now uses Why-3 for all provers (Cf. deprecated -wp-prover native:alt-ergo)"
   {alt-ergo:installed}
-  "The Frama-C/Wp native support for Coq is deprecated and only activated with Coq.8.12.x (use TIP or Why-3 instead)."
+  "The Frama-C/Wp native support for Coq is deprecated and only activated with Coq.8.13.x (use TIP or Why-3 instead)."
   {coq:installed}
 ]