`findnz` fail for adjoint sparse matrix

[ErikQQY]

findnz on a regular sparse matrix or vector is working fine, but as for the adjoint of the sparse matrix, it would error about missing dispatches.

MWE:

julia> using SparseArrays

julia> a = sprand(5, 5, 0.3)
5×5 SparseMatrixCSC{Float64, Int64} with 10 stored entries:
 0.0427685  0.200511  0.671743  0.218248   ⋅ 
  ⋅          ⋅         ⋅         ⋅        0.187924
  ⋅         0.550776   ⋅        0.575211   ⋅ 
 0.818149    ⋅         ⋅        0.765981   ⋅ 
  ⋅          ⋅         ⋅         ⋅        0.67016

julia> findnz(a)
([1, 4, 1, 3, 1, 1, 3, 4, 2, 5], [1, 1, 2, 2, 3, 4, 4, 4, 5, 5], [0.04276845834332266, 0.8181492402324447, 0.20051143143705996, 0.5507758664465765, 0.671743090935252, 0.21824817491559279, 0.5752107151129244, 0.7659814619199559, 0.18792429490108353, 0.6701601805330932])

julia> findnz(a')
ERROR: MethodError: no method matching findnz(::LinearAlgebra.Adjoint{Float64, SparseMatrixCSC{Float64, Int64}})
The function `findnz` exists, but no method is defined for this combination of argument types.

Closest candidates are:
  findnz(::Union{SparseArrays.AbstractCompressedVector{Tv, Ti}, SubArray{Tv, 1, <:SparseArrays.AbstractSparseMatrixCSC{Tv, Ti}, Tuple{Base.Slice{Base.OneTo{Int64}}, Int64}, false}, SubArray{Tv, 1, <:AbstractSparseVector{Tv, Ti}, Tuple{Base.Slice{Base.OneTo{Int64}}}, false}} where {Tv, Ti})
   @ SparseArrays ~/.julia/juliaup/julia-1.11.4+0.aarch64.apple.darwin14/share/julia/stdlib/v1.11/SparseArrays/src/sparsevector.jl:904
  findnz(::SparseArrays.AbstractSparseMatrixCSC{Tv, Ti}) where {Tv, Ti}
   @ SparseArrays ~/.julia/juliaup/julia-1.11.4+0.aarch64.apple.darwin14/share/julia/stdlib/v1.11/SparseArrays/src/sparsematrix.jl:1930

Stacktrace:
 [1] top-level scope
   @ REPL[11]:1

[ViralBShah]

This should be a straightforward PR.