bug(table): sticky cell bottom border disappear

### 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

mat-table cells inside sticky column can have their bottom border not showing depending on screen resolution and other cells content.

The issue seems to occurs whenever a content inside another cell is on multiple lines.

### Reproduction

StackBlitz link: https://stackblitz.com/edit/ck7hvid5-de9nrqus?file=src%2Fexample%2Ftable-sticky-columns-example.html,src%2Fexample%2Ftable-sticky-columns-example.ts

### Expected Behavior


### Actual Behavior


### Environment

Angular CLI: 19.2.0
Node: 18.20.3
Package Manager: npm 10.2.3
OS: linux x64

Angular: 19.2.0
... animations, cli, common, compiler, compiler-cli, core, forms
... localize, platform-browser, platform-browser-dynamic, router

Package Version
------------------------------------------------------------
@angular-devkit/architect 0.1902.0
@angular-devkit/build-angular 19.2.0
@angular-devkit/core 19.2.0
@angular-devkit/schematics 19.2.0
@angular/cdk 19.2.1
@angular/material 19.2.1
@angular/material-moment-adapter 19.2.1
@schematics/angular 19.2.0
rxjs 7.4.0
typescript 5.8.2
zone.js 0.15.0

リンクされた StackBlitz の再現から始め、特に src/example/table-sticky-columns-example.html と src/example/table-sticky-columns-example.ts を確認し、異なる画面解像度で複数行のコンテンツを含む sticky 列のテーブルを再現します。関係する Angular Material のテーブルのスタイル設定とレンダリングを追跡します；報告されたケースで sticky セルに下辺の境界線が一貫して表示されれば完了です。

索引モデルが issue の本文から書いたものです。