Bump @openzeppelin/contracts from 4.9.3 to 4.9.6 in /client

Bumps [@openzeppelin/contracts](https://github.com/OpenZeppelin/openzeppelin-contracts) from 4.9.3 to 4.9.6.
- [Release notes](https://github.com/OpenZeppelin/openzeppelin-contracts/releases)
- [Changelog](https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/CHANGELOG.md)
- [Commits](OpenZeppelin/openzeppelin-contracts@v4.9.3...v4.9.6)

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

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

client/yarn.lock

@@ -256,9 +256,9 @@
     "@openzeppelin/contracts" "^4.2.0"
 
 "@openzeppelin/contracts@^4.2.0":
-  version "4.9.3"
-  resolved "https://registry.yarnpkg.com/@openzeppelin/contracts/-/contracts-4.9.3.tgz#00d7a8cf35a475b160b3f0293a6403c511099364"
-  integrity sha512-He3LieZ1pP2TNt5JbkPA4PNT9WC3gOTOlDcFGJW4Le4QKqwmiNJCRt44APfxMxvq7OugU/cqYuPcSBzOw38DAg==
+  version "4.9.6"
+  resolved "https://registry.yarnpkg.com/@openzeppelin/contracts/-/contracts-4.9.6.tgz#2a880a24eb19b4f8b25adc2a5095f2aa27f39677"
+  integrity sha512-xSmezSupL+y9VkHZJGDoCBpmnB2ogM13ccaYDWqJTfS3dbuHkgjuwDFUmaFauBCboQMGB/S5UqUl2y54X99BmA==
 
 "@sindresorhus/is@^4.0.0", "@sindresorhus/is@^4.6.0":
   version "4.6.0"