Bump submodules/vipr from 1737fb5 to 6a77938

Bumps [submodules/vipr](https://github.com/microsoft/vipr) from `1737fb5` to `6a77938`.
- [Release notes](https://github.com/microsoft/vipr/releases)
- [Commits](microsoft/Vipr@1737fb5...6a77938)

---
updated-dependencies:
- dependency-name: submodules/vipr
  dependency-type: direct:production
...

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

Author: dependabot[bot]