Bump version and fix VoA length checks for RecursiveArrayTools v4

- Bump version to 7.102.0
- Update RecursiveArrayTools compat to include v4
- Fix length(Δu) and length(Δ) checks in concrete_solve.jl adjoint
  backpass: use length(.u) for AbstractVectorOfArray since v4 changed
  length() to return total scalar elements instead of number of inner
  arrays

Co-Authored-By: Chris Rackauckas <accounts@chrisrackauckas.com>
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: ChrisRackauckas

Project.toml

@@ -1,6 +1,6 @@
 name = "SciMLSensitivity"
 uuid = "1ed8b502-d754-442c-8d5d-10ac956f44a1"
-version = "7.101.0"
+version = "7.102.0"
 authors = ["Christopher Rackauckas <accounts@chrisrackauckas.com>", "Yingbo Ma <mayingbo5@gmail.com>"]
 
 [deps]

src/concrete_solve.jl

@@ -709,7 +709,7 @@ function SciMLBase._concrete_solve_adjoint(
                         Δu isa AbstractArray{<:AbstractArray} ||
                             Δu isa AbstractVectorOfArray
                     ) &&
-                        length(Δu) == 1 && i == 1
+                        (Δu isa AbstractVectorOfArray ? length(Δu.u) : length(Δu)) == 1 && i == 1
                     # user did sol[end] on only_end
                     x = Δu isa AbstractVectorOfArray ? Δu.u[1] : Δu[1]
                     if _save_idxs isa Number
@@ -795,7 +795,7 @@ function SciMLBase._concrete_solve_adjoint(
             if only_end
                 eltype(Δ) <: NoTangent && return
                 if (Δ isa AbstractArray{<:AbstractArray} || Δ isa AbstractVectorOfArray) &&
-                        length(Δ) == 1 && i == 1
+                        (Δ isa AbstractVectorOfArray ? length(Δ.u) : length(Δ)) == 1 && i == 1
                     # user did sol[end] on only_end
                     x = Δ isa AbstractVectorOfArray ? Δ.u[1] : Δ[1]
                     if _save_idxs isa Number