gh-149324: Raise OSError for msvcrt getch() without console

[purushothamanlabi]

Summary

Fix msvcrt.getch(), getche(), getwch(), and getwche() to raise OSError when no console is attached, instead of returning EOF/WEOF sentinel values as normal input.

Issue

• msvcrt.getch() returns EOF sentinel as data when no console is attached #149324

Testing

• Reviewed the source and generated changes locally
• Attempted PCbuild\\amd64\\python_d.exe -m test -v -u gui test_msvcrt
• Full local Windows test verification was blocked by unrelated stale/inconsistent extension build artifacts during rebuild

[python-cla-bot]

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