build: Bump minimum Qt version to 5.11.3

Author: hebasto

configure.ac

@@ -1289,7 +1289,7 @@ else
   BITCOIN_QT_INIT
 
   dnl sets $bitcoin_enable_qt, $bitcoin_enable_qt_test, $bitcoin_enable_qt_dbus
-  BITCOIN_QT_CONFIGURE([5.9.5])
+  BITCOIN_QT_CONFIGURE([5.11.3])
 
   dnl Keep a copy of the original $QT_INCLUDES and use it when invoking qt's moc
   QT_INCLUDES_UNSUPPRESSED=$QT_INCLUDES

doc/dependencies.md

@@ -20,7 +20,7 @@ These are the dependencies currently used by Bitcoin Core. You can find instruct
 | PCRE |  |  |  |  | [Yes](https://github.com/bitcoin/bitcoin/blob/master/depends/packages/qt.mk) |
 | Python (tests) |  | [3.6](https://www.python.org/downloads) |  |  |  |
 | qrencode | [3.4.4](https://fukuchi.org/works/qrencode) |  | No |  |  |
-| Qt | [5.15.2](https://download.qt.io/official_releases/qt/) | [5.9.5](https://github.com/bitcoin/bitcoin/issues/20104) | No |  |  |
+| Qt | [5.15.2](https://download.qt.io/official_releases/qt/) | [5.11.3](https://github.com/bitcoin/bitcoin/pull/24132) | No |  |  |
 | SQLite | [3.32.1](https://sqlite.org/download.html) | [3.7.17](https://github.com/bitcoin/bitcoin/pull/19077) |  |  |  |
 | XCB |  |  |  |  | [Yes](https://github.com/bitcoin/bitcoin/blob/master/depends/packages/qt.mk) (Linux only) |
 | systemtap ([tracing](tracing.md))| [4.5](https://sourceware.org/systemtap/ftp/releases/) |  |  |  | |

src/qt/guiutil.cpp

@@ -888,11 +888,7 @@ void PolishProgressDialog(QProgressDialog* dialog)
 
 int TextWidth(const QFontMetrics& fm, const QString& text)
 {
-#if (QT_VERSION >= QT_VERSION_CHECK(5, 11, 0))
     return fm.horizontalAdvance(text);
-#else
-    return fm.width(text);
-#endif
 }
 
 void LogQtInfo()