Bug(Dialog): Dialog size is fixed and can't be changed

### Is this a regression?

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

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

16-

### Description

Exist a property that make all dialogs appear at the same exact size at this class:

.cdk-overlay-pane.mat-mdc-dialog-panel
max-width: var(--mat-dialog-container-max-width, 80vw);

If you replace it with this at style.scss now it works fine and resize based on your elements
.cdk-overlay-pane.mat-mdc-dialog-panel {
max-width: 100% !important;
}

### Reproduction

StackBlitz link: No link
Steps to reproduce:
1. use a dialog and try change your modal size using dialog config ex. width: '100%'

const dialogConfig: MatDialogConfig = {
hasBackdrop: true,
disableClose: true,
width: '100%'
};

At past versions it dosnt matter, resize based on your styles and structure.

### Expected Behavior

Dialog resize based on component structure

### Actual Behavior

Dialog size appear fixed and can't change base on component elements

### Environment

- Angular: 18.0.3
- CDK/Material: 18.0.3
- Browser(s): Chrome
- Operating System (e.g. Windows, macOS, Ubuntu): Windows 11

Inizia riproducendo il problema con l'impostazione width di Angular Material's MatDialogConfig e ispeziona la regola max-width di .cdk-overlay-pane.mat-mdc-dialog-panel descritta nel report. Confronta il comportamento attuale delle dimensioni della finestra di dialogo con quello della versione precedente; il lavoro è completato quando la larghezza della finestra di dialogo risponde al valore configurato e al contenuto del componente senza richiedere un override globale con !important.

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