Merge "jQuery: Remove jQuery 1 legacy option"

diff --cc RELEASE-NOTES-1.31
index 19c135c,c228817..3c22e78
--- 1/RELEASE-NOTES-1.31
--- 2/RELEASE-NOTES-1.31
+++ b/RELEASE-NOTES-1.31
@@@ -9,10 -9,12 +9,13 @@@ production
  * $wgEnableAPI and $wgEnableWriteAPI are now deprecated and will be removed in
    a future version. The API is now considered to be stable, secure and
    essential.
+ * $wgUsejQueryThree was removed, as it is now the default. This was documented as a
+   temporary variable during the migration period, deprecated since 1.29.
+ * …
  
  === New features in 1.31 ===
 -* …
 +* Wikimedia\Rdbms\IDatabase->select() and similar methods now support
 +  joins with parentheses for grouping.
  
  === External library changes in 1.31 ===