Remove spock-core from spock module (#10069)

Author: eddumelendez

modules/spock/build.gradle

@@ -6,7 +6,7 @@ description = "Testcontainers :: Spock-Extension"
 
 dependencies {
     api project(':testcontainers')
-    api 'org.spockframework:spock-core:2.3-groovy-4.0'
+    implementation 'org.spockframework:spock-core:2.3-groovy-4.0'
 
     testImplementation project(':selenium')
     testImplementation project(':mysql')