ClangCodeModel: Switch off clangd persistently

... after failed machine suitability check.

Fixes: QTCREATORBUG-28441
Change-Id: Ic0fb956168204d8023ff96f92ae3fcd7cea8b0e9
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

src/plugins/cppeditor/cppcodemodelsettings.cpp

@@ -218,6 +218,12 @@ bool ClangdSettings::useClangd() const
 
 void ClangdSettings::setUseClangd(bool use) { instance().m_data.useClangd = use; }
 
+void ClangdSettings::setUseClangdAndSave(bool use)
+{
+    setUseClangd(use);
+    instance().saveSettings();
+}
+
 bool ClangdSettings::hardwareFulfillsRequirements()
 {
     instance().m_data.haveCheckedHardwareReqirements = true;