Update dependency: deps/haskell-backend_release (#4933)

**Also pins Lean toolchain for klean codegen.**

CI integration test `klean/test_generate` started failing independently
of the haskell-backend bump: the klean template's `lean-toolchain` was
set to `stable`, so `lake build` in the generated project floated to the
latest stable Lean. v4.31.0 added `ByteArray.decEq` to core, which
collides with the definition the template emits (`Prelude.lean:226`),
failing the build with `` `ByteArray.decEq` has already been declared
``. Pinned the template's `lean-toolchain` to `leanprover/lean4:v4.30.0`
(last stable before the conflict; verified locally that v4.29.1 and
v4.30.0-rc2 compile the generated `ByteArray.decEq` cleanly).

Follow-up (out of scope): the template still hand-rolls
`ByteArray.decEq`; to move to Lean ≥4.31 it should drop that and use
core's `DecidableEq ByteArray`.

---------

Co-authored-by: devops <devops@runtimeverification.com>
Co-authored-by: Everett Hildenbrandt <everett.hildenbrandt@gmail.com>
Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>

Author: 4 people

deps/haskell-backend_release

@@ -1 +1 @@
-v0.1.152
+v0.1.154

flake.lock

@@ -8,7 +8,7 @@
     llvm-backend.inputs.nixpkgs.follows = "nixpkgs";
 
     haskell-backend = {
-      url = "github:runtimeverification/haskell-backend/v0.1.152";
+      url = "github:runtimeverification/haskell-backend/v0.1.154";
       inputs.rv-nix-tools.follows = "rv-nix-tools";
       inputs.nixpkgs.follows = "nixpkgs";
     };

flake.nix

@@ -1 +1 @@
-stable
+leanprover/lean4:v4.30.0