[LyX/master] Remove workaround for Qt version which is no longer supported

[Juergen Spitzmueller]

commit 466e6eb613494725fea4f908392b92d9bb27344b
Author: Juergen Spitzmueller <spitz at lyx.org>
Date:   Sat Mar 11 16:43:08 2023 +0100

    Remove workaround for Qt version which is no longer supported
---
 src/frontends/qt/FancyLineEdit.cpp |   10 ++--------
 1 files changed, 2 insertions(+), 8 deletions(-)

diff --git a/src/frontends/qt/FancyLineEdit.cpp b/src/frontends/qt/FancyLineEdit.cpp
index 666ad5f..570d6cc 100644
--- a/src/frontends/qt/FancyLineEdit.cpp
+++ b/src/frontends/qt/FancyLineEdit.cpp
@@ -140,15 +140,9 @@ void FancyLineEdit::checkButtons(const QString &text)
 
 void FancyLineEdit::setClearButton(bool visible)
 {
-// QLineEdit::setClearButtonEnabled() has been implemented in Qt 5.2.
-// In earlier Qt versions, we roll our own button
-#if QT_VERSION < 0x050200
-	setButtonPixmap(FancyLineEdit::Right, getPixmap("images/", "editclear", "svgz,png"));
-	setButtonVisible(FancyLineEdit::Right, visible);
-	setAutoHideButton(FancyLineEdit::Right, true);
-#else
+	// QLineEdit::setClearButtonEnabled() has been implemented in Qt 5.2.
+	// This is now the minimum required version
 	setClearButtonEnabled(visible);
-#endif
 }