bump selenide from 5.20.4 to 5.21.0 (via #584)

Author: dependabot[bot]

allure-selenide/build.gradle.kts

@@ -2,7 +2,7 @@ description = "Allure Selenide Integration"
 
 val agent: Configuration by configurations.creating
 
-val selenideVersion = "5.20.4"
+val selenideVersion = "5.21.0"
 
 dependencies {
     agent("org.aspectj:aspectjweaver")