`rmul!`/`lmul!` are incorrect with complex scalars

[mikmoore]

Using RectangularFullPacked v0.2.1 on Julia v1.11.5.

The functions rmul! and lmul! do not apply a complex scalar correctly. One of the blocks of the receives the incorrect conjugation.

julia> TriangularRFP(fill(complex(1f0), 3, 3), :U) # initial matrix
3×3 TriangularRFP{ComplexF32}:
 1.0+0.0im  1.0+0.0im  1.0+0.0im
 0.0+0.0im  1.0+0.0im  1.0+0.0im
 0.0+0.0im  0.0+0.0im  1.0+0.0im

julia> rmul!(TriangularRFP(fill(complex(1f0), 3, 3), :U), 1f0im)
3×3 TriangularRFP{ComplexF32}:
 0.0-1.0im  0.0+1.0im  0.0+1.0im
 0.0+0.0im  0.0+1.0im  0.0+1.0im
 0.0+0.0im  0.0+0.0im  0.0+1.0im

julia> lmul!(1f0im, TriangularRFP(fill(complex(1f0), 3, 3), :U))
3×3 TriangularRFP{ComplexF32}:
 0.0-1.0im  0.0+1.0im  0.0+1.0im
 0.0+0.0im  0.0+1.0im  0.0+1.0im
 0.0+0.0im  0.0+0.0im  0.0+1.0im

Notice that the (1,1) entry is incorrectly conjugated in the above examples.

Originally added in #8. @dmbates.