revert changes to unicode linter

Author: JovanGerb

Mathlib/Tactic/Linter/TextBased/UnicodeLinter.lean

@@ -183,11 +183,6 @@ public def emojis : Array Char := #[
   .ofNat 0x1F3C1   -- 🏁️
 ]
 
-/-- Unicode symbols in mathlib that have no restrictions on which selector they are followed by. -/
-public def maybeEmojis : Array Char := #[
-  '⚠' -- ⚠️
-]
-
 /-- Unicode symbols in mathlib that should always be followed by the text variant selector. -/
 public def nonEmojis : Array Char := #[]
 
@@ -215,7 +210,6 @@ public def isAllowedCharacter (c : Char) : Bool :=
   || withVSCodeAbbrev.contains c
   || othersInMathlib.contains c
   || emojis.contains c
-  || maybeEmojis.contains c
   || nonEmojis.contains c
   || unrestricted.contains c
   || c == UnicodeVariant.emoji