doc: call out import.meta is only supported in ES modules

PR-URL: #56186
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Michaël Zasso <targos@protonmail.com>

Author: antonk52

doc/api/esm.md

@@ -340,7 +340,7 @@ modules it can be used to load ES modules.
 * {Object}
 
 The `import.meta` meta property is an `Object` that contains the following
-properties.
+properties. It is only supported in ES modules.
 
 ### `import.meta.dirname`