EVM-584 Panic -> send on closed channel inside syncer

[igorcrevar]

Description

Bug fix for panic that occurs frequently on CI unit tests

panic: send on closed channel

goroutine 1185 [running]:

[github.com/0xPolygon/polygon-edge/syncer.(*syncPeerClient](http://github.com/0xPolygon/polygon-edge/syncer.(*syncPeerClient)).handleStatusUpdate(0xc0026cc500, {0x1086380?, 0xc002a38690}, {0xc0028e9ec0, 0x27})

 /home/runner/work/polygon-edge/polygon-edge/syncer/client.go:219 +0x216

[Network Graph · 0xPolygon/polygon-edge](http://github.com/0xPolygon/polygon-edge/network.(*Topic) ).readLoop.func2()

 /home/runner/work/polygon-edge/polygon-edge/network/gossip.go:106 +0xcb

created by [Network Graph · 0xPolygon/polygon-edge](http://github.com/0xPolygon/polygon-edge/network.(*Topic) ).readLoop

 /home/runner/work/polygon-edge/polygon-edge/network/gossip.go:98 +0x14a

Changes include

• Bugfix (non-breaking change that solves an issue)
• Hotfix (change that solves an urgent issue, and requires immediate attention)
• New feature (non-breaking change that adds functionality)
• Breaking change (change that is not backwards-compatible and/or changes current functionality)

Checklist

• I have assigned this PR to myself
• I have added at least 1 reviewer
• I have added the relevant labels
• I have updated the official documentation
• I have added sufficient documentation in code

Testing

• I have tested this code with the official test suite
• I have tested this code manually

[Stefan-Ethernal]

LGTM. Really glad this is finally resolved 🚀

[vcastellm]

🎩