Revert "Add ≡ (equivalent to ==) and ≢ (equivalent to !=)"

This reverts commit ecf177c.

Author: JJ

doc/Language/unicode_ascii.pod6

@@ -112,8 +112,6 @@ X<|«>X<|»>X<|×>X<|÷>X<|≤>X<|≥>X<|≠>X<|−>X<|∘>X<|≅>X<|π>X<|τ>X<
   ⊖      |  U+2296   | (^)        |
   ⊍      |  U+228D   | (.)        |
   ⊎      |  U+228E   | (+)        |
-  ≡      |  U+2261   | ==         | Rakudo v2020.07+
-  ≢      |  U+2262   | ==         | Rakudo v2020.07+
 
 =head2 Atomic operators