Add Pierre to official contacts (#12694) (#12695)

As part of onboarding Pierre to the core team.

Also add contacts in alphabetical order

(cherry picked from commit a01dca5)

Co-authored-by: Bruno Oliveira <nicoddemus@gmail.com>

Author: patchback[bot]

doc/en/contact.rst

@@ -33,10 +33,11 @@ Mail
   discussed in public. Mails sent there will be distributed among the members
   in the pytest core team, who can also be contacted individually:
 
-  * Ronny Pfannschmidt (:user:`RonnyPfannschmidt`, `ronny@pytest.org <mailto:ronny@pytest.org>`_)
-  * Florian Bruhin (:user:`The-Compiler`, `florian@pytest.org <mailto:florian@pytest.org>`_)
   * Bruno Oliveira (:user:`nicoddemus`, `bruno@pytest.org <mailto:bruno@pytest.org>`_)
+  * Florian Bruhin (:user:`The-Compiler`, `florian@pytest.org <mailto:florian@pytest.org>`_)
+  * Pierre Sassoulas (:user:`Pierre-Sassoulas`, `pierre@pytest.org <mailto:pierre@pytest.org>`_)
   * Ran Benita (:user:`bluetech`, `ran@pytest.org <mailto:ran@pytest.org>`_)
+  * Ronny Pfannschmidt (:user:`RonnyPfannschmidt`, `ronny@pytest.org <mailto:ronny@pytest.org>`_)
   * Zac Hatfield-Dodds (:user:`Zac-HD`, `zac@pytest.org <mailto:zac@pytest.org>`_)
 
 Other