The line number on the SQL Editor in DBeaver
Window > Preferences > General > Editors > Text Editors Then, select the checkbox "Show Line Numbers"
I found it:
Right click on left column of SQL Editor and click Show / Hide Line Numbers from context menu.
In version 188.8.131.52105021514 it looks like this:
Windows > Preferences > Editors > Text Editors > Show line numbers
It is under Window / Preferences / Editors / Text Editors:
In older versions it was under Window / Preferences / General / Editors / Text Editors.
But as @simhumileco pointed out, there is a shortcut in the context menu when you right-click the left gutter of the editor.