remove async threads when terraform-boot is activated

src/main/java/org/eclipse/xpanse/terraform/boot/terraform/service/TerraformDirectoryService.java

@@ -164,6 +164,7 @@ public TerraformPlan getTerraformPlanFromDirectory(TerraformPlanFromDirectoryReq
                                                        String moduleDirectory) {
         String result = executor.getTerraformPlanAsJson(request.getVariables(),
                 request.getEnvVariables(), moduleDirectory);
+        deleteWorkspace(executor.getModuleFullPath(moduleDirectory));
         return TerraformPlan.builder().plan(result).build();
     }