Support for disabling some shadows

[damisparks]

Summary

Currently, MUI does not allow overriding the Shadows without augmenting the interface.
24 values are quite a lot to choose from. In our use case, we are okay with 3 values.

Since the current Shadows does not allow overrides unless you override the whole list of 24 values.
It would be beneficial to have a way of turning off the values that are not used.

Examples

For example, in the Typography component, we override the variants and disable them via the TypographyPropsVariantOverrides interface.

See the docs Adding & disabling variants. This functionality could be extended to the Shadows.

Motivation

The use case varies across different applications. However, the chances that a design system will have 24 shadow values are almost zero. In our design system, we agreed to have 2 to 3 shadow values.

Hence, being able to disable the ones that are not used is beneficial.

My suggestion is a bit related to this: #28820, but not the same thing.

Search keywords: shadow overrides

[siriwatknp]

Agree, let's fix this.