changelog: mention the recent hg next fixes

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branch : stable
8 jobs for topic/stable/topic-next in 7 minutes and 11 seconds (queued for 2 seconds)
Status Job ID Name Coverage
  Test
passed #188994
checks-py2

00:01:24

passed #188995
checks-py3

00:01:39

passed #189000
doc

00:00:32

manual #188993
allowed to fail manual
pytype
passed #188996
tests-py2-cext

00:05:06

passed #188997
tests-py2-pure

00:04:01

passed #188998
tests-py3-cext

00:07:10

passed #188999
tests-py3-pure

00:07:00