Chore: Increase Playwright test timeouts and reduce test flakiness

[personalizedrefrigerator]

Summary

This pull request attempts to address recent Playwright-related test failures in CI (and locally) by increasing test timeouts.

Possible future work

At present, each test runs Joplin's database migrations to create a new profile. Creating a test profile once, then re-using a copy of it for all tests could improve test performance.

[personalizedrefrigerator]

The goal of this change is to work around the following occasional test failure:

Error: locator.waitFor: Error: strict mode violation: getByAltText('large-jpg-image-with-exif-rotation.jpg') resolved to 2 elements:
➤ YN0000: [@joplin/app-desktop]:         1) <img title="" data-from-md="" alt="large-jpg-image-with-exif-rotation.jpg" data-resource-id="3379eea703504dbfb1b949db385a0abe" src="joplin-content://note-viewer//Users/runner/work/joplin/joplin/packages/app-desktop/integration-tests/test-profile/1M2urBZZBp2RhdaiCwPMhA/resources//3379eea703504dbfb1b949db385a0abe.jpg?t=1742052371936"/> aka getByRole('img', { name: 'large-jpg-image-with-exif-' }).first()
➤ YN0000: [@joplin/app-desktop]:         2) <img title="" data-from-md="" alt="large-jpg-image-with-exif-rotation.jpg" data-resource-id="9ee801938bf84de3b1ed3210526954c3" src="joplin-content://note-viewer//Users/runner/work/joplin/joplin/packages/app-desktop/integration-tests/test-profile/1M2urBZZBp2RhdaiCwPMhA/resources//9ee801938bf84de3b1ed3210526954c3.jpg?t=1742052371811"/> aka getByRole('img', { name: 'large-jpg-image-with-exif-' }).nth(1)
➤ YN0000: [@joplin/app-desktop]: 
➤ YN0000: [@joplin/app-desktop]:     Call log:
➤ YN0000: [@joplin/app-desktop]:       - waiting for locator('.rli-editor').locator('iframe[src$="note-viewer/index.html"]').frameLocator(':scope').getByAltText('large-jpg-image-with-exif-rotation.jpg')
➤ YN0000: [@joplin/app-desktop]: 
➤ YN0000: [@joplin/app-desktop]: 
➤ YN0000: [@joplin/app-desktop]:        at util/getImageSourceSize.ts:6
➤ YN0000: [@joplin/app-desktop]: 
➤ YN0000: [@joplin/app-desktop]:       4 | 	// Use state: 'attached' -- we don't need the image to be on the screen (just present
➤ YN0000: [@joplin/app-desktop]:       5 | 	// in the DOM).
➤ YN0000: [@joplin/app-desktop]:     > 6 | 	await imageLocator.waitFor({ state: 'attached' });
➤ YN0000: [@joplin/app-desktop]:         | 	                   ^
➤ YN0000: [@joplin/app-desktop]:       7 |
➤ YN0000: [@joplin/app-desktop]:       8 | 	// We load a copy of the image to avoid returning an overriden width set with
➤ YN0000: [@joplin/app-desktop]:       9 | 	//    .width = some_number

It may also make sense to check the image attachment logic to verify that it doesn't attach images to a note twice in certain cases.