doc: remove repeated word in modules.md

PR-URL: https://github.com/nodejs/node/pull/32931
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Zeyu Yang <himself65@outlook.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Juan José Arboleda <soyjuanarbol@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>

doc/api/modules.md

@@ -1031,7 +1031,7 @@ added: v13.7.0
 
 > Stability: 1 - Experimental
 
-Helpers for for interacting with the source map cache. This cache is
+Helpers for interacting with the source map cache. This cache is
 populated when source map parsing is enabled and
 [source map include directives][] are found in a modules' footer.