path: fix normalization of Windows device paths missing colon

[HassanFleyah]

Description

This PR fixes an inconsistency in path.win32.normalize() where Windows reserved device names prefixed with \\.\ or \\?\ were not being correctly detected if they lacked a trailing colon.

Current behavior:

• path.normalize('\\\\.\\CON:') -> Correctly handled/sanitized.
• path.normalize('\\\\.\\CON') -> Returned as-is (Inconsistent).

This change ensures that \\.\CON and \\?\CON are treated consistently with other device paths by strictly checking against the reserved names list when the namespace prefix is present but the colon is missing.

Context

This addresses an edge case where valid Windows device paths bypass normalization logic due to the missing colon expectation.

Testing

I have verified this fix locally.

[nodejs-github-bot]

Review requested:

• @nodejs/path

[Copilot]

Pull request overview

This PR tightens path.win32.normalize() handling for Windows device paths so that reserved device names prefixed with \\.\ or \\?\ are correctly detected even when the trailing colon is missing. It aims to close an edge case where such paths could bypass existing normalization logic.

Changes:

• Refactors the UNC/device-root detection branch in win32.normalize() to special-case firstPart === '.' || firstPart === '?' for device roots.
• Adds new logic to detect reserved device names when a \\.\ or \\?\ namespace prefix is present but the path lacks a colon, using WINDOWS_RESERVED_NAMES directly on the substring after the prefix.

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