Add 2025.2 TC chair and vice-chair

The chair nomination process was advertised and discussed
at the TC meeting on 2025-03-04 [1]. The results were
announced during the TC meeting on 2025-03-11 [2].
Dmitriy confirmed his willingness to remain vice-chair on
2025-03-12 [3].

[1] https://meetings.opendev.org/meetings/tc/2025/tc.2025-03-04-18.00.log.html#l-85
[2] https://meetings.opendev.org/meetings/tc/2025/tc.2025-03-11-18.00.log.html#l-76
[3] https://meetings.opendev.org/irclogs/%23openstack-tc/%23openstack-tc.2025-03-12.log.html#t2025-03-12T08:31:42

Change-Id: Ib9461897090701c7b7eb6ed275398c86a7f018e1

reference/members.yaml

@@ -24,14 +24,14 @@
     email: gouthampravi@gmail.com
     memberid: 35705
     date: February 2025
-    role: null
+    role: chair
 
   - name: Dmitriy Rabotyagov
     irc: noonedeadpunk
     email: noonedeadpunk@gmail.com
     memberid: 107517
     date: February 2025
-    role: null
+    role: vice-chair
 
   - name: Artem Goncharov
     irc: gtema