Do not show any minibuffer when using spacemacs/window-split-triple-columns

[lesteve]

I noticed that SPC w 3 i.e. spacemacs/window-split-triple-columns always shows a inactive minibuffer e.g. a buffer like *Minibuf-1*, *Minibuf-2*.

Here is a screenshot that shows an example where I do SPC w 3:

When you switch to the window with a minibuffer, the key bindings are not the spacemacs ones and you need to do C-x b to switch to a different buffer which makes the user experience not so great. This affects SPC w 4 as well.

To reproduce it, start emacs, and then SPC w 3, one of the window should be a *Minibuf-<some-number>*.

This used to work at one point and I traced it back to https://github.com/syl20bnr/spacemacs/pull/15520 that removed the #'buffer-file-name filter when splitting windows with SPC w 3. The PR relies on #'persp-contain-buffer-p instead but this is not filtering out minibuffers if you are in the Default layout. For completeness, personally I don't use layouts.

System Info :computer:

• OS: gnu/linux
• Emacs: 29.1
• Spacemacs: 0.999.0
• Spacemacs branch: develop (rev. c46a22da1)
• Graphic display: t
• Running in daemon: nil
• Distribution: spacemacs
• Editing style: vim
• Completion: helm
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               (mu4e :variables mu4e-installation-path "/usr/local/share/emacs/site-lisp/mu4e")
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