Simplify nil guard in font kerning

Co-authored-by: Codex <codex@openai.com>

Author: Gabriel-Darbord

src/ArrowSyntaxRendering/ASRSubstitutionFont.class.st

@@ -246,10 +246,9 @@ ASRSubstitutionFont >> installOn: aDisplayContext foregroundColor: foregroundCol
 { #category : 'measuring' }
 ASRSubstitutionFont >> kerningLeft: leftCharacter right: rightCharacter [
 
-	((self hides: leftCharacter) or: [
-		 rightCharacter notNil and: [ self hides: rightCharacter ] ])
-		ifTrue: [ ^ 0 ].
+	(self hides: leftCharacter) ifTrue: [ ^ 0 ].
 	rightCharacter ifNil: [ ^ 0 ].
+	(self hides: rightCharacter) ifTrue: [ ^ 0 ].
 	^ self baseFont
 		  kerningLeft: (self displayCharacterFor: leftCharacter)
 		  right: (self displayCharacterFor: rightCharacter)