Fix lettuce testing dependency exposure

Author: trask

instrumentation/lettuce/lettuce-5.1/testing/build.gradle.kts

@@ -8,7 +8,7 @@ dependencies {
   // 6.0+ added protocolVersion access which allows forcing RESP2 for consistency in tests
   compileOnly("io.lettuce:lettuce-core:6.0.0.RELEASE")
 
-  implementation("org.testcontainers:testcontainers")
+  api("org.testcontainers:testcontainers")
   implementation("com.google.guava:guava")
 
   implementation("io.opentelemetry:opentelemetry-api")