Bump @openzeppelin/contracts-upgradeable from 3.4.2-solc-0.7 to 4.9.6

Bumps [@openzeppelin/contracts-upgradeable](https://github.com/OpenZeppelin/openzeppelin-contracts-upgradeable) from 3.4.2-solc-0.7 to 4.9.6.
- [Release notes](https://github.com/OpenZeppelin/openzeppelin-contracts-upgradeable/releases)
- [Changelog](https://github.com/OpenZeppelin/openzeppelin-contracts-upgradeable/blob/master/CHANGELOG.md)
- [Commits](OpenZeppelin/openzeppelin-contracts-upgradeable@v3.4.2-solc-0.7...v4.9.6)

---
updated-dependencies:
- dependency-name: "@openzeppelin/contracts-upgradeable"
  dependency-type: indirect
...

Signed-off-by: dependabot[bot] <support@github.com>