fix(deps): update credentials to v1.6.0

Author: descope[bot]

gradle/libs.versions.toml

@@ -2,7 +2,7 @@
 agp = "9.0.0"
 kotlin = "2.3.0"
 browser = "1.9.0"
-credentials = "1.5.0"
+credentials = "1.6.0"
 googleid = "1.2.0"
 json = "20251224"
 junit = "4.13.2"