Overwrite margin-bottom on form-control-static (#21270)

Overwrite margin-bottom on form-control-static (#21270)

* Overwrite margin-bottom on form-control-static

In the documentation the form-control-static class has been used on a p element.
On the regular vertical form the margin bottom of the p element gets overwritten by a mb-0 class.
In the inline form example this class hasn't been applied, therefore the p element gets a margin-bottom.

To prevent this behavior we can add a margin-bottom of 0.

* Update _forms.scss