There's a merged pull request on the void-packages repository

Update discord to 0.0.20
https://github.com/void-linux/void-packages/pull/39305

Description:
Bump discord version to 0.0.20 and update checksum.

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#### Testing the changes
- I tested the changes in this PR: **YES**

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#### Local build testing
- I built this PR locally for my native architecture, x86_64-glibc