WIP: qt-build-utils: default to qmake, qmake6, qmake-qt5

When using Nix with Qt 6 the output of qmake6 -query is incorrect
and ends up pointing to the incorrect locations. But qmake -query
points to the correct ones.

This solves the issue for Nix but looks like Debian only has
qmake for Qt 5 and qmake6 for Qt 6.

Related to KDAB#590

crates/qt-build-utils/src/lib.rs

@@ -254,7 +254,7 @@ impl QtBuild {
         }
 
         // Fedora 36 renames Qt5's qmake to qmake-qt5
-        let candidate_executable_names = ["qmake6", "qmake-qt5", "qmake"];
+        let candidate_executable_names = ["qmake", "qmake6", "qmake-qt5"];
         for (index, executable_name) in candidate_executable_names.iter().enumerate() {
             match verify_candidate(executable_name) {
                 Ok((executable_name, version)) => {