type: close の E2E テストを追加する

[voluntas]

This pull request includes several updates to the configuration files, workflow files, and the addition of new tests and examples. The key changes focus on updating the environment configuration, modifying GitHub Actions workflows, and adding new E2E tests and examples.

Environment Configuration:

• Added VITE_SORA_API_URL to .env.template for specifying the Sora API URL.

GitHub Actions Workflow Updates:

• Updated the runs-on parameter to ubuntu-24.04 in multiple workflow files (ci.yaml, e2e-test.yml, and npm-pkg-e2e-test.yml). [1] [2] [3]
• Added tailscale/github-action@v2 to e2e-test.yml and npm-pkg-e2e-test.yml for setting up Tailscale. [1] [2]

New Examples:

• Added a new example for data_channel_signaling_only with index.html and main.mts files to demonstrate Sora SDK usage. [1] [2]

E2E Tests:

• Added new E2E tests for type: close and type: switched in tests/type_close.spec.ts and tests/type_switched.spec.ts. [1] [2]
• Removed old E2E test for sendonly type: switched in tests/switched.spec.ts.

Miscellaneous:

• Updated CHANGES.md to include the addition of the new E2E test for "type": "close".
• Disabled CORS in playwright.config.mts by adding relevant Chrome flags.
• Added a new entry for data_channel_signaling_only in vite.config.mjs.