chore: bump @openzeppelin/defender-sdk-proposal-client

Bumps [@openzeppelin/defender-sdk-proposal-client](https://github.com/OpenZeppelin/defender-sdk) from 1.15.2 to 2.7.0.
- [Release notes](https://github.com/OpenZeppelin/defender-sdk/releases)
- [Commits](https://github.com/OpenZeppelin/defender-sdk/compare/@openzeppelin/defender-sdk-proposal-client@1.15.2...@openzeppelin/defender-sdk-proposal-client@2.7.0)

---
updated-dependencies:
- dependency-name: "@openzeppelin/defender-sdk-proposal-client"
  dependency-version: 2.7.0
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

packages/defender-sdk/package.json

@@ -24,7 +24,7 @@
     "@openzeppelin/defender-sdk-monitor-client": "^1.15.0",
     "@openzeppelin/defender-sdk-action-client": "^1.15.0",
     "@openzeppelin/defender-sdk-relay-client": "^1.15.0",
-    "@openzeppelin/defender-sdk-proposal-client": "^1.15.0",
+    "@openzeppelin/defender-sdk-proposal-client": "^2.7.0",
     "@openzeppelin/defender-sdk-deploy-client": "^1.15.0",
     "@openzeppelin/defender-sdk-notification-channel-client": "^1.15.0",
     "@openzeppelin/defender-sdk-relay-signer-client": "^1.15.0",