Fix allocation in auto_jacvec!

Before:
```julia
julia> @Btime auto_jacvec!($dy, $f, $x, $v, $cache1, $cache2);
  99.454 μs (1200 allocations: 32.81 KiB)
```

After:
```julia
julia> @Btime auto_jacvec!($dy, $f, $x, $v, $cache1, $cache2);
  44.668 μs (0 allocations: 0 bytes)
```

Co-authored-by: Chris Elrod <[email protected]>

Author: YingboMa

src/differentiation/jaches_products.jl

@@ -9,7 +9,7 @@ function auto_jacvec!(
     cache1 = Dual{typeof(ForwardDiff.Tag(DeivVecTag(),eltype(x))),eltype(x),1}.(x, ForwardDiff.Partials.(Tuple.(reshape(v, size(x))))),
     cache2 = similar(cache1),
 )
-    cache1 .= Dual{typeof(ForwardDiff.Tag(DeivVecTag(),eltype(x))),eltype(x),1}.(x, ForwardDiff.Partials.(Tuple.(reshape(v, size(x)))))
+    cache1 .= Dual{typeof(ForwardDiff.Tag(DeivVecTag(),eltype(x))),eltype(x),1}.(x, ForwardDiff.Partials.(tuple.(reshape(v, size(x)))))
     f(cache2, cache1)
     vecdy = _vec(dy)
     vecdy .= partials.(_vec(cache2), 1)