chore: update Playwright.NET to v1.56.0

[lucassc]

This PR updates Playwright.NET to version 1.56.0 to align with the upstream Playwright driver.

Changes

• Bump AssemblyVersion from 1.55.0 to 1.56.0
• Update DriverVersion to 1.56.0
• Docker images will be built with Playwright 1.56.0 drivers

Playwright 1.56.0 Highlights

This aligns with Playwright 1.56.0 which includes:

• Playwright Agents: Three custom agent definitions (planner, generator, healer) for LLM-guided test building
• New APIs:
  • page.consoleMessages() and page.pageErrors() for retrieving recent console messages
  • page.requests() for retrieving recent network requests
• UI Mode and HTML Reporter enhancements
• Browser versions: Chromium 141.0.7390.37, Firefox 142.0.1, WebKit 26.0

Related Links

• Playwright 1.56.0 release: https://github.com/microsoft/playwright/releases/tag/v1.56.0
• Driver rolled to 1.56.1: chore: roll driver to 1.56.1 #3250

Testing

• Docker builds will be validated via CI
• All existing tests should pass with the updated driver version

cc @microsoft/playwright-dotnet-maintainers

[yury-s]

We are handling it as a part of the release.