[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_

首先运行为 swagger/swagger-generator/generator-core 提供的 idflakies Maven 命令，并检查调用 SwaggerOperations.generate(...) 的测试。跟踪共享的 swaggerOperations 状态如何在各个测试方法之间进行初始化和清除。完成的标准是上述测试在随机化的执行顺序下都能通过。

由索引模型根据 Issue 内容生成。