Update doc/api/esm.md

Co-authored-by: Antoine du Hamel <[email protected]>

Author: guybedford

doc/api/esm.md

@@ -669,8 +669,7 @@ imported from the same path.
 
 <!-- YAML
 changes:
-  - version:
-    - REPLACEME
+  - version: REPLACEME
     pr-url: https://github.com/nodejs/node/pull/57038
     description: Wasm modules no longer require the `--experimental-wasm-modules` flag.
 -->