fix (timeline block): set attribute timelineIsLast

[mxkae]

Issue:

• the line in last timeline block does not end at the middle.
• only happens on the frontend
• caused by fix: fixes freezing when creating synced patterns #3245

Screenshot:

Expected:

[github-actions]

🤖 Pull request artifacts

file	commit
pr3292-stackable-3292-merge.zip	06646c4

[github-actions]

Try this Pull Request in the WordPress playground: https://playground.wordpress.net/?mode=seamless#{"landingPage":"/wp-admin/post-new.php?post_type=page","preferredVersions":{"php":"latest","wp":"latest"},"steps":[{"step":"login","username":"admin","password":"password"},{"step":"installPlugin","pluginZipFile":{"resource":"url","url":"https://raw.githubusercontent.com/gambitph/Stackable/artifacts/pr3292-stackable-3292-merge.zip"}}]}

[andeng1106]

@mxkae @bfintal
When I create a new synced pattern or added an existing synced pattern, the page freezes. Tested on 3.13.5 also but no issue for that version.

Created synced pattern

Screen.Recording.2024-09-23.at.3.mp4

Added existing synced pattern

Screen.Recording.2024-09-23.at.3.1.mp4