fix: set correct Dencun Mainnet epoch

src/common/config/env.validation.ts

@@ -39,10 +39,7 @@ export enum WorkingMode {
 }
 
 const dencunForkEpoch = {
-  /**
-   * @todo This should be corrected once the particular epoch of the Dencun hard fork on Mainnet is known.
-   */
-  '1': 300000,
+  '1': 269568,
   '5': 231680,
   '17000': 29696,
 };