chore(docs): bump changelog for 5.3.0.

Author: spencer-tb

docs/CHANGELOG.md

@@ -10,6 +10,20 @@ Test fixtures for use by clients are available for each release on the [Github r
 
 ### 🛠️ Framework
 
+#### `fill`
+
+#### `consume`
+
+### 📋 Misc
+
+### 🧪 Test Cases
+
+## [v5.3.0](https://github.com/ethereum/execution-spec-tests/releases/tag/v5.3.0) - 2025-10-08
+
+### 💥 Breaking Change
+
+### 🛠️ Framework
+
 - ✨ Add benchmark-specific test wrapper (`benchmark_test`) that supports **EIP-7825** and create a benchmark code generator for common test pattern ([#1945](https://github.com/ethereum/execution-spec-tests/pull/1945)).
 
 #### `fill`