Remove Spaceless Block From Textarea Widgets

Leaving it in can only mangle values from data bound to the form.

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #11277
| License       | MIT
| Doc PR        | 

The tests pass here, but it doesn't seem like any tests really cover the actual rendering.