Parse created_at via Time.new instead of Time.iso8601

A full ISO-8601 timestamp with seconds (the format compact index v2
sends, e.g. 2026-05-30T08:52:10Z) is recognised by Time.new directly,
so we can drop the require "time" and the indirection through
Time.iso8601 while keeping the same ArgumentError fallback for
malformed input.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

Author: hsbt

bundler/lib/bundler/endpoint_specification.rb

@@ -165,11 +165,10 @@ def parse_metadata(data)
         when "created_at"
           value = v.is_a?(Array) ? v.last : v
           if value.is_a?(String)
-            require "time"
-            begin
-              @created_at = Time.iso8601(value)
+            @created_at = begin
+              Time.new(value)
             rescue ArgumentError
-              @created_at = nil
+              nil
             end
           end
         end