Use TOML.Parser for TOML parsing w/ Dates support

This behavior had actually subtly changed with JuliaLang/julia#54755
so that this no longer returned Dates objects, but sticking to the
public `TOML.Parser` interface should prevent that from being an issue
after JuliaLang/julia#55020 lands.

src/Registry/registry_instance.jl

@@ -15,8 +15,7 @@ function to_tar_path_format(file::AbstractString)
 end
 
 # See loading.jl
-const TOML_CACHE = let parser = Base.TOML.Parser()
-    parser.Dates = Dates
+const TOML_CACHE = let parser = TOML.Parser()
     Base.TOMLCache(parser, Dict{String, Dict{String, Any}}())
 end
 const TOML_LOCK = ReentrantLock()
@@ -26,9 +25,8 @@ function parsefile(in_memory_registry::Union{Dict, Nothing}, folder::AbstractStr
         return _parsefile(joinpath(folder, file))
     else
         content = in_memory_registry[to_tar_path_format(file)]
-        parser = Base.TOML.Parser(content; filepath=file)
-        parser.Dates = Dates
-        return Base.TOML.parse(parser)
+        parser = TOML.Parser(content; filepath=file)
+        return TOML.Internals.parse(parser)
     end
 end
 

src/Types.jl

@@ -53,8 +53,7 @@ function deepcopy_toml(x::Dict{String, Any})
 end
 
 # See loading.jl
-const TOML_CACHE = let parser = Base.TOML.Parser()
-    parser.Dates = Dates
+const TOML_CACHE = let parser = TOML.Parser()
     Base.TOMLCache(parser, Dict{String, Dict{String, Any}}())
 end
 const TOML_LOCK = ReentrantLock()