bug(form-field): Outlined form-field should have enough space to contain floating label

### Is this a regression?

- [ ] Yes, this behavior used to work in the previous version

### The previous version in which this bug was not present was

_No response_

### Description

When using `outline` appearance for `mat-form-field`, the floating label overflows out of component itself. The `mat-form-field` component should have enough space on top to contain floating label. See below screenshot for reference:

### Reproduction

StackBlitz link: https://stackblitz.com/edit/rxp9hmcc?file=src%2Fexample%2Fform-field-appearance-example.html

### Expected Behavior

The `mat-form-field` component should have enough space (margin) on top to contain floating label.

### Actual Behavior

The `mat-form-field` component does not have enough space (margin) on top to contain floating label.

### Environment

- Angular: 20
- CDK/Material: 20
- Browser(s): Chrome
- Operating System (e.g. Windows, macOS, Ubuntu): macOS

Inizia dalla riproduzione StackBlitz collegata e dal relativo esempio di aspetto del campo del modulo, quindi esamina il layout e gli stili del mat-form-field outlined di Angular Material coinvolti nell’etichetta flottante. Il lavoro è completato quando il componente outlined fornisce spazio sufficiente nella parte superiore per l’etichetta flottante senza overflow nella configurazione segnalata con Angular 20, Chrome e macOS.

Scritto dal modello di indicizzazione a partire dal testo della issue.