test: disable page-drag tests in headed linux

[yury-s]

The tests have been flaking across browsers apparently due to stray mouse event sent by the OS.

See https://devops.playwright.dev/flakiness.html#filter_spec=page%2Fpage-drag.spec.ts&show_flaky=true&timestamp=1718225128508

[github-actions]

Test results for "tests 1"

2 failed
❌ [playwright-test] › runner.spec.ts:118:5 › should ignore subprocess creation error because of SIGINT
❌ [playwright-test] › test-step.spec.ts:604:5 › should show final toPass error

3 flaky

⚠️ [playwright-test] › ui-mode-test-screencast.spec.ts:21:5 › should show screenshots
⚠️ [webkit-page] › page/workers.spec.ts:243:3 › should support offline
⚠️ [playwright-test] › ui-mode-test-watch.spec.ts:96:5 › should batch watch updates

28313 passed, 637 skipped
✔️✔️✔️

Merge workflow run.