Fix changelog

Author: jamesnw

CHANGELOG.md

@@ -5,10 +5,9 @@
 * **Potentially breaking bug fix**: Selectors with unmatched brackets now always
   produce a parser error. Previously, some edge cases like `[foo#{"]:is(bar"}) {a:
   b}` would compile without error, but this was an unintentional bug.
-## 1.83.5-dev
 
 * Fix the error message for `@extend` without a selector and possibly other
-  parsing edge-cases in contexts that allow interpolation..
+  parsing edge-cases in contexts that allow interpolation.
 
 ## 1.83.4