ocamlPackages.git: 3.2.0 -> 3.3.0; ocamlPackages.irmin: 2.4.0 -> 2.5.1 (#113717)

* ocamlPackages.git: 3.2.0 -> 3.3.0

* minor fixes to tests (while introducing new failures in the nix
  sandbox we have to patch)
* compatibility fixes to commit messages with git fsck and github at the
  expense of potentially breaking older ocaml-git managed repositories.

https://github.com/mirage/ocaml-git/releases/tag/3.3.0

* ocamlPackages.irmin: 2.4.0 -> 2.5.1

* irmin-graphql: enable tests as they now work without network
* irmin-layers: tests were removed
* ppx_irmin: tests were removed

Compatibility with git 3.3.0 and improved performance.

https://github.com/mirage/irmin/releases/tag/2.5.0
https://github.com/mirage/irmin/releases/tag/2.5.1

* ocamlPackages.{git, irmin}: add myself to maintainers

pkgs/development/ocaml-modules/irmin/default.nix

@@ -1,5 +1,5 @@
 { lib, buildDunePackage
-, astring, base64, digestif, fmt, jsonm, logs, ocaml_lwt, ocamlgraph, uri
+, astring, digestif, fmt, jsonm, logs, ocaml_lwt, ocamlgraph, uri
 , repr, ppx_irmin, bheap
 }:
 
@@ -13,7 +13,6 @@ buildDunePackage {
 
   propagatedBuildInputs = [
     astring
-    base64
     digestif
     fmt
     jsonm