Rename icon to prevent install conflicts with the Qt6 frontend.

--- qt5/icons/Makefile.in.orig	2025-07-28 07:07:41 UTC
+++ qt5/icons/Makefile.in
@@ -350,7 +350,7 @@ EXTRA_DIST = data-error.svg \
 top_builddir = @top_builddir@
 top_srcdir = @top_srcdir@
 EXTRA_DIST = data-error.svg \
-	     pinentry.png \
+	     pinentry-qt5.png \
 	     hint.svg \
 	     password-generate.svg \
 	     visibility.svg \
@@ -358,7 +358,7 @@ EXTRA_DIST = data-error.svg \
 	     password-generate_dark.svg \
 	     visibility_dark.svg
 
-icons_DATA = pinentry.png
+icons_DATA = pinentry-qt5.png
 iconsdir = $(datadir)/pixmaps
 all: all-am