[CLEANUP] Remove CSSBlockList::allDeclarationBlocks() (#1239)

Change the one remaining usage instance to use `getAllDeclarationBlocks()`,
which was refactored in #990.

Part of #994.

Author: JakeQZ

src/CSSList/CSSBlockList.php

@@ -41,20 +41,6 @@ public function getAllDeclarationBlocks(): array
         return $result;
     }
 
-    /**
-     * @param list<DeclarationBlock> $result
-     */
-    protected function allDeclarationBlocks(array &$result): void
-    {
-        foreach ($this->contents as $item) {
-            if ($item instanceof DeclarationBlock) {
-                $result[] = $item;
-            } elseif ($item instanceof CSSBlockList) {
-                $item->allDeclarationBlocks($result);
-            }
-        }
-    }
-
     /**
      * Returns all `RuleSet` objects recursively found in the tree, no matter how deeply nested the rule sets are.
      *
@@ -111,9 +97,7 @@ protected function allValues(
      */
     protected function allSelectors(array &$result, ?string $specificitySearch = null): void
     {
-        $declarationBlocks = [];
-        $this->allDeclarationBlocks($declarationBlocks);
-        foreach ($declarationBlocks as $declarationBlock) {
+        foreach ($this->getAllDeclarationBlocks() as $declarationBlock) {
             foreach ($declarationBlock->getSelectors() as $selector) {
                 if ($specificitySearch === null) {
                     $result[] = $selector;