subprocess.run timeout does not function if shell=True and capture_output=True

Bug report

Bug description:

I am using python 3.12.4 on windows 10 and when calling subprocess.run("powershell", shell=True, capture_output=True, timeout=1) code execution seems to suspend indefinetly as the process now accepts the user input and interprets it.

This behaviour matches the one described in #81605 despite it having supposedly been fixed 5 years ago.
For example when calling subprocess.run("cmd", shell=True, capture_output=True, timeout=1) and then entering echo o>f.txt a new file called "f.txt" gets created with "o" as its content.

When using the IDLE Shell the process completes nearly instandly and returns this:

CompletedProcess(args='powershell', returncode=0, stdout=b'Windows PowerShell\r\nCopyright (C) Microsoft Corporation. Alle Rechte vorbehalten.\r\n\r\nLernen Sie das neue plattform\x81bergreifende PowerShell kennen - https://aka.ms/pscore6\r\n\r\nPS C:\Users\Mabeeck\Desktop\Python> ', stderr=b'')

The same applies for Python 3.8.9, 3.9.2, 3.10.6, 3.11.5 and 3.13.0b3
I'll apoligise in advance, if my impression of the bug beeing supposed to be fixed is wrong.

CPython versions tested on:

3.8, 3.9, 3.10, 3.11, 3.12, 3.13

Operating systems tested on:

Windows

從 Windows 上使用 shell=True、capture_output=True 和 timeout=1 的 subprocess.run 入口點開始，重現回報的 powershell 和 cmd 情況。比較所列 Python 版本之間的行為，並確定子程序接受輸入時應發生什麼 timeout 行為；當無限期暫停問題獲得解決，且該行為由適當的回歸測試涵蓋時，issue 即完成。