[submodule] Update submodule sonic-snmpagent to the latest HEAD automatically (#16576)

#### Why I did it
src/sonic-snmpagent
```
* 64f0def - (HEAD -> 202012, origin/202012) Support interface speed for PortChannels (#262) (2 days ago) [Lukas Stockner]
```
This commit is contained in:
mssonicbld 2023-09-19 02:03:12 +08:00 committed by GitHub
parent ee7eaa298d
commit 7aeb2fb69e
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@ -1 +1 @@
Subproject commit b292c01124faae1d7bcdcd45ab5ddce06a43b64a Subproject commit 64f0def9275f6bc6275f51093ba641fb140178e8