emoji: Convert :| to :neutral:.

Previously we converted it to 😑 (which however has closed
eyes). :neutral: has open eyes and therefore more closely resembles :|

tools/setup/emoji/emoji_setup_utils.py

@@ -40,7 +40,7 @@ EMOTICON_CONVERSIONS = {
     '(:': ':slight_smile:',
     ':(': ':frown:',
     '<3': ':heart:',
-    ':|': ':expressionless:',
+    ':|': ':neutral:',
     ':/': ':confused:',
     ';)': ':wink:',
     ':D': ':grinning:',