[DOC] Update for Pathname.ctime (ruby#17370)

Author: BurdetteLamar

pathname_builtin.rb

@@ -1169,50 +1169,29 @@ def birthtime() File.birthtime(@path) end
   # see {File System Timestamps}[rdoc-ref:file/timestamps.md]:
   #
   # ```ruby
-  # # Work in a temporary directory.
-  # Pathname.mktmpdir do |tmpdirpath|
-  #   # A subdirectory therein, and its Pathname.
-  #   dirpath = File.join(tmpdirpath, 'subdir')
-  #   dir_pn = Pathname(dirpath)
-  #   puts "Create directory; directory ctime established."
-  #   dir_pn.mkdir
-  #   puts "  Directory ctime: #{dir_pn.ctime}"
-  #   sleep(1)
-  #
-  #   # A file in the subdirectory, and its Pathname.
-  #   filepath = File.join(dirpath, 't.txt')
-  #   file_pn = Pathname(filepath)
-  #   puts "Create file; file ctime established; directory ctime updated."
-  #   file_pn.write('foo')
-  #   puts "  File ctime:      #{file_pn.ctime}"
-  #   puts "  Directory ctime: #{dir_pn.ctime}"
-  #   sleep(1)
-  #   puts "Write file; file ctime updated; directory ctime not updated."
-  #   file_pn.write('bar')
-  #   puts "  File ctime:      #{file_pn.ctime}"
-  #   puts "  Directory ctime: #{dir_pn.ctime}"
-  #   sleep(1)
-  #   puts "Read file; neither ctime not updated."
-  #   file_pn.read
-  #   puts "  File ctime:      #{file_pn.ctime}"
-  #   puts "  Directory ctime: #{dir_pn.ctime}"
-  # end
-  # ```
-  #
-  # Output:
-  #
-  # ```text
-  # Create directory; directory ctime established.
-  #   Directory ctime: 2026-05-20 14:05:05 -0500
-  # Create file; file ctime established; directory ctime updated.
-  #   File ctime:      2026-05-20 14:05:06 -0500
-  #   Directory ctime: 2026-05-20 14:05:06 -0500
-  # Write file; file ctime updated; directory ctime not updated.
-  #   File ctime:      2026-05-20 14:05:07 -0500
-  #   Directory ctime: 2026-05-20 14:05:06 -0500
-  # Read file; neither ctime not updated.
-  #   File ctime:      2026-05-20 14:05:07 -0500
-  #   Directory ctime: 2026-05-20 14:05:06 -0500
+  # # A directory and its Pathname.
+  # dir_path = 'doc/foo'
+  # dir_pn = Pathname(dir_path)
+  # # Create directory; directory ctime established.
+  # dir_pn.mkdir
+  # dir_pn.ctime  # => 2026-06-16 16:44:15.86720572 -0500
+  # # A file therein and its Pathname.
+  # file_path = dir_pn.join('t.tmp')
+  # file_pn = Pathname(file_path)
+  # # Create file; file ctime established; directory ctime updated.
+  # file_pn.write('foo')
+  # file_pn.ctime # => 2026-06-16 16:46:00.734974872 -0500
+  # dir_pn.ctime  # => 2026-06-16 16:46:00.734974872 -0500
+  # # Write file; file ctime updated; directory ctime not updated.
+  # file_pn.write('bar')
+  # file_pn.ctime # => 2026-06-16 16:49:11.421204188 -0500
+  # dir_pn.ctime  # => 2026-06-16 16:46:00.734974872 -0500
+  # # Read file; neither ctime updated.
+  # file_pn.read
+  # file_pn.ctime # => 2026-06-16 16:49:11.421204188 -0500
+  # dir_pn.ctime  # => 2026-06-16 16:46:00.734974872 -0500
+  # # Clean up.
+  # dir_pn.rmtree
   # ```
   #
   def ctime() File.ctime(@path) end