doc: fix chromium document link in pull-requests.md

PR-URL: #43265
Reviewed-By: Tobias Nießen <tniessen@tnie.de>
Reviewed-By: Michael Dawson <midawson@redhat.com>
Reviewed-By: Mohammed Keyvanzadeh <mohammadkeyvanzade94@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Qingyu Deng <i@ayase-lab.com>
Reviewed-By: Darshan Sen <raisinten@gmail.com>

doc/contributing/pull-requests.md

@@ -319,7 +319,7 @@ There are a number of more advanced mechanisms for managing commits using
 Feel free to post a comment in the pull request to ping reviewers if you are
 awaiting an answer on something. If you encounter words or acronyms that
 seem unfamiliar, refer to this
-[glossary](https://sites.google.com/a/chromium.org/dev/glossary).
+[glossary](https://chromium.googlesource.com/chromiumos/docs/+/HEAD/glossary.md).
 
 #### Approval and request changes workflow