Update MAINTAINERS.md (#1491)

Exclude Andrei Gumilev

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## What this PR does


### Release note

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```release-note
[]
```

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## Summary by CodeRabbit

* **Documentation**
* Updated the Maintainers documentation to reflect the current team by
removing an outdated entry.
* Improves accuracy of ownership and contact information for project
stewardship.

* **Chores**
* Performed repository housekeeping to keep governance information
current.
  * No changes to product functionality; no user-facing impact.

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MAINTAINERS.md

@@ -7,7 +7,6 @@
 | Kingdon Barrett | [@kingdonb](https://github.com/kingdonb) | Urmanac | FluxCD and flux-operator |
 | Timofei Larkin | [@lllamnyp](https://github.com/lllamnyp) | 3commas | Etcd-operator Lead |
 | Artem Bortnikov | [@aobort](https://github.com/aobort) | Timescale | Etcd-operator Lead |
-| Andrei Gumilev | [@chumkaska](https://github.com/chumkaska) | Ænix | Platform Documentation |
 | Timur Tukaev | [@tym83](https://github.com/tym83) | Ænix | Cozystack Website, Marketing, Community Management |
 | Kirill Klinchenkov | [@klinch0](https://github.com/klinch0) | Ænix | Core Maintainer |
 | Nikita Bykov | [@nbykov0](https://github.com/nbykov0) | Ænix | Maintainer of ARM and stuff |