[TASK] Drop support for vendor-prefixed keyframe selectors

CHANGELOG.md

@@ -51,7 +51,7 @@ Please also have a look at our
 - Drop magic method forwarding in `OutputFormat` (#898)
 - Drop `atRuleArgs()` from the `AtRule` interface (#1141)
 - Remove `OutputFormat::get()` and `::set()` (#1108, #1110)
-- Drop special support for vendor prefixes (#1083)
+- Drop special support for vendor prefixes (#1083, #1175)
 - Remove the IE hack in `Rule` (#995)
 - Drop `getLineNo()` from the `Renderable` interface (#1038)
 - Remove `OutputFormat::level()` (#874)

tests/ParserTest.php

@@ -787,23 +787,6 @@ public function selectorIgnoresInFile(): void
         self::assertSame($expected, $document->render());
     }
 
-    /**
-     * @test
-     */
-    public function keyframeSelectors(): void
-    {
-        $document = self::parsedStructureForFile(
-            'keyframe-selector-validation',
-            Settings::create()->withMultibyteSupport(true)
-        );
-        $expected = '@-webkit-keyframes zoom {0% {-webkit-transform: scale(1,1);}'
-            . "\n\t"
-            . '50% {-webkit-transform: scale(1.2,1.2);}'
-            . "\n\t"
-            . '100% {-webkit-transform: scale(1,1);}}';
-        self::assertSame($expected, $document->render());
-    }
-
     /**
      * @test
      */