Fix deprecation warning on Formatting.jl package! v1.2.1

Formatting.jl is deprecated (as of March, 2024), in favour of
JuliaString's Format.jl.  The API we are using to format numbers is
the same, and this dependency change does not change any of the
functionality for users of SpelledOut.jl.

This fix was implemented by @pmc4.

See merge request #57

Project.toml

@@ -1,7 +1,7 @@
 name = "SpelledOut"
 uuid = "4728c690-e668-4265-bc0d-51a8c0f93067"
 authors = ["Jake W. Ireland <jakewilliami@icloud.com> and contributors"]
-version = "1.2.0"
+version = "1.2.1"
 
 [deps]
 DecFP = "55939f99-70c6-5e9b-8bb0-5071ed7d61fd"