Promote @astencel-sumo to Maintainer (#32008)

Andrzej contributed a lot to the repository. The maintainers propose to
promote Andrzej to Maintainer.

.github/auto_assign.yml

@@ -12,14 +12,14 @@ assigneeGroups:
   approvers_maintainers:
     # Approvers
     - Aneurysm9
-    - astencel-sumo
     - atoulme
     - bryan-aguilar
     - crobert-1
     - dashpole
     - songy23
     - fatsheep9146
     # Maintainers
+    - astencel-sumo
     - bogdandrutu
     - codeboten
     - djaglowski

README.md

@@ -87,7 +87,6 @@ Emeritus Triagers:
 
 Approvers ([@open-telemetry/collector-contrib-approvers](https://github.com/orgs/open-telemetry/teams/collector-contrib-approvers)):
 
-- [Andrzej Stencel](https://github.com/astencel-sumo), Sumo Logic
 - [Anthony Mirabella](https://github.com/Aneurysm9), AWS
 - [Antoine Toulme](https://github.com/atoulme), Splunk
 - [Bryan Aguilar](https://github.com/bryan-aguilar), AWS
@@ -104,6 +103,7 @@ Emeritus Approvers:
 Maintainers ([@open-telemetry/collector-contrib-maintainer](https://github.com/orgs/open-telemetry/teams/collector-contrib-maintainer)):
 
 - [Alex Boten](https://github.com/codeboten), Honeycomb
+- [Andrzej Stencel](https://github.com/astencel-sumo), Sumo Logic
 - [Bogdan Drutu](https://github.com/bogdandrutu), Snowflake
 - [Daniel Jaglowski](https://github.com/djaglowski), observIQ
 - [Dmitrii Anoshin](https://github.com/dmitryax), Splunk