minor #16230 fix a small grammar issue (xabbuh)

This PR was merged into the 4.4 branch.

Discussion
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fix a small grammar issue

Commits
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d8da247 fix a small grammar issue

Author: javiereguiluz

contributing/code/core_team.rst

@@ -109,7 +109,7 @@ Symfony contributions:
 Core Membership Application
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-About once a year, the core team discuss the opportunity to invite new members.
+About once a year, the core team discusses the opportunity to invite new members.
 
 Core Membership Revocation
 ~~~~~~~~~~~~~~~~~~~~~~~~~~