Fix typo in WATCHLISTS.

An accidental `|` at the end of the regex meant it was matching every
CL.

Change-Id: I3898a58c8825f2b534aa751bf1368a9df874e295
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6226840
Reviewed-by: Elly FJ <ellyjones@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1414951}

WATCHLISTS

@@ -905,7 +905,7 @@
       'filepath': 'content/browser/renderer/clipboard|' \
                   'content/browser/web_contents/.*drag|' \
                   'ui/base/clipboard/|'\
-                  'ui/base/dragdrop/|'
+                  'ui/base/dragdrop/'
     },
     'commerce': {
       'filepath': 'components/commerce/|'\