update inference reflection usage for 1.10

Author: KristofferC

test/compiler/inference.jl

@@ -5166,9 +5166,9 @@ issue55882_nfields(x::Union{T,Nothing}) where T<:Number = nfields(x)
 @test only(Base.return_types(issue55882_nfields)) <: Int
 
 # JuliaLang/julia#56248
-@test only(Base.infer_return_type() do
+@test only(Base.return_types() do
     TypeVar(:Issue56248, 1)
 end) === Union{}
-@test only(Base.infer_return_type() do
+@test only(Base.Base.return_types() do
     TypeVar(:Issue56248, Any, 1)
 end) === Union{}