Remove Synthesize Deprecated

[anthony-murphy]

Once we remove deprecated on IFluidDependecySynthsize, and DependencyContainer we should do the following:

yeah. there is another set of changes coming. once i no longer expose providers directly i can just create the PropertyDescriptions upfront on register, and then all this code will be way simpler. I do those change with what you suggest in the next release

Originally posted by @anthony-murphy in #8593 (comment)