Simulate typing out the clipboard contents! Save the below script as an AppleScript or a service in Automator.

simulate_typing_clipboard.txt

set mytext to (the clipboard as text)

write_string(mytext)

on write_string(the_string)
	tell application "System Events"
		launch
		repeat with the_character in the_string
			keystroke the_character
			delay (random number from 0.05 to 0.25)
		end repeat
	end tell
end write_string

simulate_typing_clipboard_cope_with_autoindent.txt

# based on https://christianheilmann.com/2014/01/09/autmating-typing-in-screencasts-with-applescript-or-how-to-look-like-a-hollywood-hacker/
set my_text to (the clipboard as text)

set the text item delimiters to (ASCII character 13) # CR, not LF!
set my_lines to text items in my_text
repeat with current_line in my_lines
	write_string(current_line)
end repeat

on write_string(the_string)
	tell application "System Events"
		launch
		repeat with the_character in the_string
			keystroke the_character
			delay (random number from 0.01 to 0.12)
		end repeat
		key code 36 # enter
		# Cope with autoindent by deleting to start of line
		key code 123 using {shift down, command down} # left arrow
		key code 51 # delete
	end tell
end write_string

Inspired by http://christianheilmann.com/2014/01/09/autmating-typing-in-screencasts-with-applescript-or-how-to-look-like-a-hollywood-hacker/ (which includes a hack to make it work with editors where you can't turn auto-indent off).

I now have to work with an editor where I can't turn auto-indent off, so I included the aforementioned hack in simulate_typing_clipboard_cope_with_autoindent.txt.

I'd also like to point out a weird coincidence: it's been a year to the day between comments. ¯\_(ツ)_/¯