Update all patch dependencies to v1.21.3 (#15)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

gradle/libs.versions.toml

@@ -6,7 +6,7 @@ jetbrains-annotations = "26.0.2"
 junit-jupiter = "5.11.3"
 mockserver-neolight = "1.0.19"
 shrinkwrap = "1.2.6"
-testcontainers = "1.21.2"
+testcontainers = "1.21.3"
 
 [libraries]
 assertj = { module = "org.assertj:assertj-core", version.ref = "assertj" }