Fix import paths for TestableRunner classes to match legend-engine 4.72.0

Author: devin-ai-integration[bot]

showcases/src/test/java/org/example/ShowcaseCompilerTest.java

@@ -23,6 +23,9 @@
 import org.finos.legend.engine.testable.extension.TestableRunnerExtensionLoader;
 import org.finos.legend.engine.testable.model.RunTestsResult;
 import org.finos.legend.engine.testable.model.RunTestsTestableInput;
+import org.finos.legend.pure.m3.coreinstance.meta.pure.metamodel.testable.Test;
+import org.finos.legend.pure.m3.coreinstance.meta.pure.metamodel.testable.TestAccessor;
+import org.finos.legend.pure.m3.coreinstance.meta.pure.metamodel.testable.Testable;
 import org.junit.Assert;
 import org.junit.Test;
 import org.junit.runner.RunWith;