Update Selenium dependencies (#56070)

Author: MackinnonBuck

eng/Versions.props

@@ -318,8 +318,8 @@
     <MicrosoftPlaywrightVersion>1.28.0</MicrosoftPlaywrightVersion>
     <PollyExtensionsHttpVersion>3.0.0</PollyExtensionsHttpVersion>
     <PollyVersion>7.2.4</PollyVersion>
-    <SeleniumSupportVersion>4.20.0</SeleniumSupportVersion>
-    <SeleniumWebDriverVersion>4.20.0</SeleniumWebDriverVersion>
+    <SeleniumSupportVersion>4.21.0</SeleniumSupportVersion>
+    <SeleniumWebDriverVersion>4.21.0</SeleniumWebDriverVersion>
     <SerilogExtensionsLoggingVersion>1.4.0</SerilogExtensionsLoggingVersion>
     <SerilogSinksFileVersion>4.0.0</SerilogSinksFileVersion>
     <StackExchangeRedisVersion>2.7.27</StackExchangeRedisVersion>