[MINOR] Add french stop word "les"

## What changes were proposed in this pull request?

Added "les" as french stop word (plurial of le)

Author: Thomas Decaux <ebuildy@gmail.com>

Closes #18514 from ebuildy/patch-1.

mllib/src/main/resources/org/apache/spark/ml/feature/stopwords/french.txt

@@ -15,6 +15,7 @@ il
 je
 la
 le
+les
 leur
 lui
 ma
@@ -152,4 +153,4 @@ eusses
 eût
 eussions
 eussiez
-eussent
\ No newline at end of file
+eussent