Bump Sources/Copus from 61747bc to 6b6035a

Bumps [Sources/Copus](https://github.com/xiph/opus) from `61747bc` to `6b6035a`.
- [Release notes](https://github.com/xiph/opus/releases)
- [Commits](xiph/opus@61747bc...6b6035a)

---
updated-dependencies:
- dependency-name: Sources/Copus
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>