Update SharpYaml dependency to v3.x

Is your feature request related to a problem? Please describe.

OpenAPI.NET currently depends on SharpYaml v2. In my project, I use OpenAPI.NET to process OpenAPI documents and also need to read additional YAML-based configuration files.

SharpYaml v3 is a major redesign that introduces breaking changes compared to v2. Since OpenAPI.NET brings SharpYaml v2 as a dependency, I am currently forced to continue developing against the older SharpYaml API and plan a future migration.

Describe the solution you'd like

I would like OpenAPI.NET to update its SharpYaml dependency from v2 to the latest v3 release.

Describe alternatives you've considered

• Continuing to use SharpYaml v2 in my own code and migrating later.
• Isolating YAML processing behind an abstraction layer to minimize the impact of a future migration.
• Using a different YAML library for application-specific configuration files.

While these approaches are possible, they add complexity that could be avoided if OpenAPI.NET adopted SharpYaml v3 directly.

找出專案中對 SharpYaml v2 的相依性宣告，並在評估受影響的 OpenAPI YAML 處理之前，檢視 SharpYaml v3 的 breaking changes。更新相依性後執行現有的測試套件；完成的條件是使用 SharpYaml v3，且 OpenAPI 文件的 YAML 處理仍維持相容。