[BUG] - multiple order dependent flaky tests in `swagger/swagger-generator/generator-core`

### Steps to Reproduce

Several tests in the `swagger/swagger-generator/generator-core` module exhibit **order-dependent (OD) flakiness**. These tests rely on shared state through `SwaggerOperations.generate(...)` and previously used `static` fields inside the test classes. These tests previously used a `static SwaggerOperations` field that was shared across all test methods in the class, and when test methods are executed in different orders, some permutations caused a later test to run after the shared `swaggerOperations` field had already been cleared.

To reproduce:

```bash
mvn edu.illinois.cs:idflakies-maven-plugin:2.0.0:detect -pl swagger/swagger-generator/generator-core -am -Ddt.randomize.rounds=30 -Ddt.detector.original_order.all_must_pass=false
```

### Expected Behavior

Mentioned tests should pass with different orders.

### Servicecomb Version

3.3.0

### Additional Context

_No response_

Commencez par exécuter la commande Maven idflakies fournie pour swagger/swagger-generator/generator-core et examinez les tests qui appellent SwaggerOperations.generate(...). Suivez la manière dont l’état partagé de swaggerOperations est initialisé et réinitialisé entre les méthodes de test. C’est terminé lorsque les tests mentionnés passent avec des ordres d’exécution aléatoires.

Rédigé par le modèle d'indexation à partir du texte de l'issue.