chore: adjust CODEOWNERS (#6327)

Remove some noise from my assignments

CODEOWNERS

@@ -4,7 +4,7 @@
 # Listed persons will automatically be asked by GitHub to review a PR touching these paths.
 # If multiple names are listed, a review by any of them is considered sufficient by default.
 
-/.github/ @Kha @kim-em
+/.github/ @kim-em
 /RELEASES.md @kim-em
 /src/kernel/ @leodemoura
 /src/lake/ @tydeu
@@ -14,9 +14,7 @@
 /src/Lean/Elab/Tactic/ @kim-em
 /src/Lean/Language/ @Kha
 /src/Lean/Meta/Tactic/ @leodemoura
-/src/Lean/Parser/ @Kha
-/src/Lean/PrettyPrinter/ @Kha
-/src/Lean/PrettyPrinter/Delaborator/ @kmill
+/src/Lean/PrettyPrinter/ @kmill
 /src/Lean/Server/ @mhuisi
 /src/Lean/Widget/ @Vtec234
 /src/Init/Data/ @kim-em