docs: Add testnet v3.1.9 upgrade binaries file #4449

Job	Run time
Build / Node binary	2m 58s
Lint / Protobuf	10s
Lint / Golang	2m 21s
Lint / Broken Markdown links	31s
Lint / Shell pipefail check	5s
Lint / Super Linter	1m 20s
Build / Docker image	2m 23s
Tests / Installer - Standalone mode	12s
Tests / Installer - Cosmovisor mode	12s
Tests / Fee Abstraction Tests	16m 26s
Tests / Integration Tests	12m 19s
Tests / Unit Tests	4m 28s
Tests / Upgrade Tests	24m 39s
Tests / Report	4s
Release	0s
	1h 8m 8s

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