[LyX/master] Revert defaulting to xcb.

[Pavel Sanda]

commit 18f11784f1b3dc23cb7d7a86ebfdeb3a9bacd67d
Author: Pavel Sanda <sanda at lyx.org>
Date:   Sun May 17 21:56:53 2026 +0200

    Revert defaulting to xcb.
    
    The reported issue is most probably problem with drivers, see #13305 and
    https://www.mail-archive.com/lyx-devel@lists.lyx.org/msg226284.html
---
 lib/lyx.desktop.in | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/lyx.desktop.in b/lib/lyx.desktop.in
index 490554833b..c158e88d58 100644
--- a/lib/lyx.desktop.in
+++ b/lib/lyx.desktop.in
@@ -5,7 +5,7 @@ Name=LyX at program_suffix@
 GenericName=Document Processor
 Comment=High level LaTeX frontend
 Keywords=WYSIWYG;WYSIWYM;TeX;LaTeX;GUI;frontend;editor;
-Exec=env QT_QPA_PLATFORM=xcb lyx at program_suffix@ %F
+Exec=lyx at program_suffix@ %F
 TryExec=lyx at program_suffix@
 Icon=lyx at program_suffix@
 StartupNotify=false