Bump minimum dune version to 3.13

Fixes dune issue: ocaml/dune#9365.

Author: sim642

dune-project

@@ -1,4 +1,4 @@
-(lang dune 3.7)
+(lang dune 3.13)
 (using dune_site 0.1)
 (cram enable)
 (name goblint)

goblint.opam

@@ -35,7 +35,7 @@ homepage: "https://goblint.in.tum.de"
 doc: "https://goblint.readthedocs.io/en/latest/"
 bug-reports: "https://github.com/goblint/analyzer/issues"
 depends: [
-  "dune" {>= "3.7"}
+  "dune" {>= "3.13"}
   "ocaml" {>= "4.14"}
   "goblint-cil" {>= "2.0.5"}
   "batteries" {>= "3.5.1"}