fix(api): make Page.screencast a property instead of a method

[pavelfeldman]

Summary

• Page.screencast was accidentally defined as a method; changed it to a readonly property, consistent with keyboard, mouse, touchscreen, etc.

[github-actions]

Test results for "MCP"

5339 passed, 186 skipped

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Merge workflow run.

[github-actions]

Test results for "tests 1"

9 failed
❌ [default] › run-tests.spec.ts:226 › should show error message @vscode-extension
❌ [default] › run-tests.spec.ts:278 › should show soft error messages @vscode-extension
❌ [default] › run-tests.spec.ts:818 › should report project-specific failures @vscode-extension
❌ [default-reuse] › run-tests.spec.ts:226 › should show error message @vscode-extension
❌ [default-reuse] › run-tests.spec.ts:278 › should show soft error messages @vscode-extension
❌ [default-reuse] › run-tests.spec.ts:818 › should report project-specific failures @vscode-extension
❌ [default-trace] › run-tests.spec.ts:226 › should show error message @vscode-extension
❌ [default-trace] › run-tests.spec.ts:278 › should show soft error messages @vscode-extension
❌ [default-trace] › run-tests.spec.ts:818 › should report project-specific failures @vscode-extension

5 flaky

⚠️ [chromium-library] › library/popup.spec.ts:261 › should not throw when click closes popup `@chromium-ubuntu-22.04-arm-node20`
⚠️ [chromium-library] › library/trace-viewer.spec.ts:1223 › should display language-specific locators `@chromium-ubuntu-22.04-node20`
⚠️ [chromium-library] › library/trace-viewer.spec.ts:1223 › should display language-specific locators `@chromium-ubuntu-22.04-node22`
⚠️ [firefox-library] › library/inspector/cli-codegen-1.spec.ts:1080 › cli codegen › should not throw csp directive violation errors `@firefox-ubuntu-22.04-node20`
⚠️ [playwright-test] › ui-mode-trace.spec.ts:700 › should indicate current test status `@macos-latest-node20`

38767 passed, 847 skipped

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Merge workflow run.