ci: use ocaml 5.4

Author: rr0gi

.github/workflows/makefile.yml

@@ -14,7 +14,7 @@ jobs:
       matrix:
         ocaml-version:
           - 4.14
-          - 5.2
+          - 5.4
 
     runs-on: ubuntu-22.04
 
@@ -37,7 +37,7 @@ jobs:
 
     - name: Pin libevent
       run: opam pin add libevent --dev
-      
+
     - name: Build
       run: opam exec -- dune build --profile=release