Missing rules for FFTW `unsafe_execute`

Here is a MWE

```julia
using Enzyme
using FFTW

Enzyme.EnzymeRules.inactive(::typeof(FFTW.assert_applicable), args...) = nothing

function test(p, x)
p*x
return sum(abs2, x)
end

x = rand(ComplexF64, 256)
p = plan_fft!(x)

test(p, x)

dx = similar(x)
autodiff(Enzyme.Reverse, test, Active, Const(p), Duplicated(x, dx))

Enzyme compilation failed.

No augmented forward pass found for ijl_lazy_load_and_lookup
at context: %fftw_execute_dft.found = call void ()* @ijl_lazy_load_and_lookup({} addrspace(10)* nonnull %11, i8* noundef getelementptr inbounds ([17 x i8], [17 x i8]* @_j_str1, i32 0, i32 0)) #21, !dbg !41

Stacktrace:
[1] unsafe_execute!
@ ~/.julia/packages/FFTW/6nZei/src/fft.jl:518
[2] *
@ ~/.julia/packages/FFTW/6nZei/src/fft.jl:835
[3] *
@ ~/.julia/packages/AbstractFFTs/4iQz5/src/definitions.jl:224
[4] test
@ ~/Research/EnzymeTest/fft.jl:8

Stacktrace:
[1] throwerr(cstr::Cstring)
@ Enzyme.Compiler ~/.julia/packages/Enzyme/aEyGD/src/compiler.jl:1696
[2] unsafe_execute!
@ ~/.julia/packages/FFTW/6nZei/src/fft.jl:518 [inlined]
[3] *
@ ~/.julia/packages/FFTW/6nZei/src/fft.jl:835 [inlined]
[4] *
@ ~/.julia/packages/AbstractFFTs/4iQz5/src/definitions.jl:224 [inlined]
[5] test
@ ~/Research/EnzymeTest/fft.jl:8 [inlined]
[6] diffejulia_test_5412wrap
@ ~/Research/EnzymeTest/fft.jl:0
[7] macro expansion
@ ~/.julia/packages/Enzyme/aEyGD/src/compiler.jl:6673 [inlined]
[8] enzyme_call
@ ~/.julia/packages/Enzyme/aEyGD/src/compiler.jl:6273 [inlined]
[9] CombinedAdjointThunk
@ ~/.julia/packages/Enzyme/aEyGD/src/compiler.jl:6150 [inlined]
[10] autodiff
@ ~/.julia/packages/Enzyme/aEyGD/src/Enzyme.jl:314 [inlined]
[11] autodiff(::ReverseMode{…}, ::typeof(test), ::Type{…}, ::Const{…}, ::Duplicated{…})
@ Enzyme ~/.julia/packages/Enzyme/aEyGD/src/Enzyme.jl:326
[12] top-level scope
@ ~/Research/EnzymeTest/fft.jl:20
Some type information was truncated. Use `show(err)` to see complete types.
```

The inactive rule is to prevent another `ijl_lazy_load_and_lookup` error, but that's easy to beat since it shouldn't be differentiated.

Unless I misunderstand something, this is another missing rule. If so, I'll take a crack at writing some rules in the next couple of days.