Add support for Julia v1.12 by fixing JET type stability warning (#559)

Author: albertomercurio

src/qobj/superoperators.jl

@@ -160,7 +160,7 @@ See also [`spre`](@ref), [`spost`](@ref), and [`lindblad_dissipator`](@ref).
 function liouvillian(
     H::AbstractQuantumObject{OpType},
     c_ops::Union{Nothing,AbstractVector,Tuple} = nothing,
-    Id_cache = I(prod(H.dimensions)),
+    Id_cache::Diagonal = I(prod(H.dimensions)),
 ) where {OpType<:Union{Operator,SuperOperator}}
     L = liouvillian(H, Id_cache)
     if !(c_ops isa Nothing)

test/core-test/code-quality/Project.toml

@@ -6,4 +6,4 @@ Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
 
 [compat]
 Aqua = "0.8"
-JET = "0.9"
+JET = "0.9, 0.10"