deps: update com.google.code.gson:gson to v2.12.0

Author: renovate[bot]

gradle/libs.versions.toml

@@ -27,7 +27,7 @@ exposed = "0.58.0"
 flexmark = "0.64.8"
 freemarker = "2.3.34"
 greenmail = "2.1.2"
-gson = "2.11.0"
+gson = "2.12.0"
 hikari = "6.2.1"
 hoplite = "2.9.0"
 jackson = "2.18.2"