`lu` seems to be ambiguous on Julia Nightly

[kellertuer]

Sometimes I check our Nightly, when they error and I noticed here that the current lu decomposition for 5x5 (but not for 4x4, 3x3 or 2x2) seems to be ambiguous currently?

  MethodError: lu(::SizedMatrix{5, 5, Float64, 2, Matrix{Float64}}, ::Val{true}) is ambiguous. Candidates:
948
    lu(A::AbstractMatrix, ::Val{true}; check) in LinearAlgebra at deprecated.jl:70
949
    lu(A::StaticMatrix{N, N}, pivot::Union{Val{false}, Val{true}}; check) where N in StaticArrays at StaticArrays/uH2MB/src/lu.jl:40
950
    lu(A::StaticMatrix, pivot::Union{Val{false}, Val{true}}; check) in StaticArrays at StaticArrays/uH2MB/src/lu.jl:33
951
  Possible fix, define
952
    lu(::StaticMatrix{N, N}, ::Val{true}) where N

This seems to come originally from our matrix exponential call here.

[fgasdia]

Just to add - I see an ambiguous lu for a 4x4 on Nightly for a package of mine: here

  Expression: [W[1] W[3]; W[2] W[4]] ≈ 2 * (L \ T) * L
  MethodError: lu(::SMatrix{4, 4, ComplexF64, 16}, ::Val{true}) is ambiguous. Candidates:
    lu(A::AbstractMatrix, ::Val{true}; check) in LinearAlgebra at deprecated.jl:70
    lu(A::StaticMatrix{N, N}, pivot::Union{Val{false}, Val{true}}; check) where N in StaticArrays at /home/runner/.julia/packages/StaticArrays/uH2MB/src/lu.jl:40
    lu(A::StaticMatrix, pivot::Union{Val{false}, Val{true}}; check) in StaticArrays at /home/runner/.julia/packages/StaticArrays/uH2MB/src/lu.jl:33
  Possible fix, define
    lu(::StaticMatrix{N, N}, ::Val{true}) where N

[mateuszbaran]

#921 should fix this.