Strange behavior of `file-exists-p` on latest Tramp version

[Ruiyang Wu]

Hi,

On Tramp version (2.6.0.2) (with Emacs 28.2), after setting (setq 
minibuffer-completing-file-name t), (file-exists-p "/ssh:") returns t, while 
(tramp-sh-handle-file-exists-p  "/ssh:") returns 'Not a Tramp file name: 
"/ssh:"'. On older versions of Tramp, (file-exists-p "/ssh:") always returns 
nil. This new behavior affects other completion systems like ivy-mode on melpa.

Best,
Ruiyang