bug(material/button): incorrect alignment of svg icons

### 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

20.0.5

### Description

After update to angular/material 20.1.+

Material buttons with icons no longer align properly.

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**Before**

**After**

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**What causing an issue?**

After removing `min-height`, everything works as before.
My icon size is 24px, but with `min-height: fit-content`, the .mat-icon container gets stretched while the SVG icon remains the same size.

For example:
- `.mat-icon: 24px × 29px`
- `svg: 24px × 24px`

This causes vertical misalignment of icons compared to previous versions.

I believe this PR is the cause of this issue.: https://github.com/angular/components/pull/30891
commit -> https://github.com/angular/components/pull/30891/commits/87b6962841454cfde8200b9c9de7ad73079416ae

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### Reproduction

StackBlitz link:
Steps to reproduce:
1.
2.

### Expected Behavior

The `.mat-icon` inside `.mat-mdc-button-base` should remain properly aligned and not stretch vertically.
The mat-icon container should match the size of the SVG icon `(24px × 24px)` when the icon size is set to `24px`.

### Actual Behavior

With `min-height: fit-content;` applied, the .mat-icon container stretches vertically `(e.g., 24px × 29px) `while the SVG icon stays 24px × 24px.
This causes misalignment and extra spacing around the icon compared to previous versions.

### Environment

- Angular: 20.1.2
- CDK/Material: 20.1.2
- Browser(s): Chrome
- Operating System (e.g. Windows, macOS, Ubuntu): macOS

`.mat-mdc-button-base` と `.mat-icon` 周辺の Angular Material のボタンスタイルを確認し、PR 30891 の commit 87b6962841454cfde8200b9c9de7ad73079416ae で導入された動作をバージョン 20.0.5 と比較します。Angular/Material 20.1.2 で 24px の SVG アイコンを使って再現し、コンテナが 24px × 24px のままであり、アイコンが垂直方向に整列されることを確認します。

索引モデルが issue の本文から書いたものです。