Sets the text within the `GtkLabel` widget.
It overwrites any text that was there before.
This function will clear any previously set mnemonic accelerators, and set the [property@Gtk.Label:use-underline property] to false as a side effect.
This function will set the [property@Gtk.Label:use-markup] property to false as a side effect.
See also: [method@Gtk.Label.set_markup]
The text you want to set