It's a bookmark -- you have bookmarked a file and not just a specific line.
Just focus the file in the Project View panel and press the same shortcut again (F11 on Windows). https://www.jetbrains.com/help/phpstorm/2020.1/navigating-through-the-source-code.html
Or just go to Favorites panel | Bookmarks node
or just straight via Boormarks popup (Navigate | Bookmarks | Show Bookmarks
-- Shift + F11) and remove it there.
Favorites | Bookmarks node (https://www.jetbrains.com/help/phpstorm/managing-your-project-favorites.html):
Show Bookmarks popup (https://www.jetbrains.com/help/phpstorm/bookmarks-dialog.html):