3ba5220839
This has been deprecated to keep selector consistent with other core Angular selectors. As element selectors are in kebab-case.
Now deprecated:
```
<ngForm #myForm="ngForm">
```
After:
```
<ng-form #myForm="ngForm">
```
You can also choose to supress this warnings by providing a config for `FormsModule` during import:
```ts
imports: [
FormsModule.withConfig({warnOnDeprecatedNgFormSelector: 'never'});
]
Closes: #23678
PR Close #23721