zcreate fails when fill_value is not the same type as the array

[felixcremer]

This is coming from the ZarrDatasets tests and used to work in 0.9

    [1] zcreate(::Type{Float32}, storage::Zarr.DirectoryStore, dims::Int64; path::String, zarr_format::Zarr.ZarrFormat{2}, chunks::Tuple{Int64}, fill_value::Float64, fill_as_missing::Bool, compressor::Zarr.BloscCompressor, filters::Nothing, attrs::Dict{String, Any}, writeable::Bool, indent_json::Bool, dimension_separator::Nothing)
      @ Zarr ~/.julia/packages/Zarr/9mGHa/src/ZArray.jl:374
    [2] zcreate(::Type{Float32}, g::Zarr.ZGroup{Zarr.DirectoryStore}, name::String, addargs::Int64; kwargs::@Kwargs{chunks::Tuple{Int64}, attrs::Dict{String, Any}, fill_value::Float64})
      @ Zarr ~/.julia/packages/Zarr/9mGHa/src/ZGroup.jl:196
    [3] defVar(ds::ZarrDataset{Nothing, Missing, Zarr.ZGroup{Zarr.DirectoryStore}}, name::String, vtype::DataType, dimensionnames::Tuple{String}; chunksizes::Nothing, attrib::Dict{Any, Any}, fillvalue::Float64, kwargs::@Kwargs{})
      @ ZarrDatasets ~/Documents/eopf-sample-notebooks/notebooks/julia_eopf_plugin/dev/ZarrDatasets/src/variable.jl:104
    [4] top-level scope
      @ ~/Documents/eopf-sample-notebooks/notebooks/julia_eopf_plugin/dev/ZarrDatasets/test/test_write.jl:49