Update dependency @openzeppelin/contracts to v4.9.6

Author: renovate[bot]

package.json

@@ -22,7 +22,7 @@
 	"devDependencies": {
 		"@nomiclabs/hardhat-ethers": "2.1.1",
 		"@nomiclabs/hardhat-waffle": "2.0.6",
-		"@openzeppelin/contracts": "4.8.1",
+		"@openzeppelin/contracts": "4.9.6",
 		"@types/chai": "4.3.20",
 		"@types/dotenv": "8.2.0",
 		"@types/mocha": "9.1.1",

yarn.lock

@@ -1369,10 +1369,10 @@
   resolved "https://registry.yarnpkg.com/@openzeppelin/contracts-upgradeable/-/contracts-upgradeable-4.9.6.tgz#38b21708a719da647de4bb0e4802ee235a0d24df"
   integrity sha512-m4iHazOsOCv1DgM7eD7GupTJ+NFVujRZt1wzddDPSVGpWdKq1SKkla5htKG7+IS4d2XOCtzkUNwRZ7Vq5aEUMA==
 
-"@openzeppelin/contracts@4.8.1":
-  version "4.8.1"
-  resolved "https://registry.yarnpkg.com/@openzeppelin/contracts/-/contracts-4.8.1.tgz#709cfc4bbb3ca9f4460d60101f15dac6b7a2d5e4"
-  integrity sha512-xQ6eUZl+RDyb/FiZe1h+U7qr/f4p/SrTSQcTPH2bjur3C5DbuW/zFgCU/b1P/xcIaEqJep+9ju4xDRi3rmChdQ==
+"@openzeppelin/contracts@4.9.6":
+  version "4.9.6"
+  resolved "https://registry.yarnpkg.com/@openzeppelin/contracts/-/contracts-4.9.6.tgz#2a880a24eb19b4f8b25adc2a5095f2aa27f39677"
+  integrity sha512-xSmezSupL+y9VkHZJGDoCBpmnB2ogM13ccaYDWqJTfS3dbuHkgjuwDFUmaFauBCboQMGB/S5UqUl2y54X99BmA==
 
 "@resolver-engine/core@^0.3.3":
   version "0.3.3"