Update retrofit monorepo to v2.12.0

Author: renovate[bot]

gradle/libs.versions.toml

@@ -8,7 +8,7 @@ jupyter-plugin = "0.12.0-398"
 okio = "3.11.0"
 moshi = "1.15.2"
 okhttp = "4.12.0"
-retrofit = "2.11.0"
+retrofit = "2.12.0"
 kotlin-coroutines = "1.10.2"
 kotlin-binary-compatibility-validator = "0.17.0"
 slf4j = "2.0.17"