musl (correctly) does not like being fed weird Qt paths from TZ.

Just use the normal Europe/Paris file already installed by tzdata.

--- kdelibs4support-5.116.0/autotests/ktimezonestest.cpp.old	2024-05-04 06:38:54.000000000 -0500
+++ kdelibs4support-5.116.0/autotests/ktimezonestest.cpp	2025-07-01 03:49:46.268079721 -0500
@@ -295,7 +295,7 @@
 
 void KTimeZonesTest::currentOffset()
 {
-    QString tzfile = ':' + mDataDir + "/Europe/Paris";
+    QString tzfile = "Europe/Paris";
     QByteArray originalZone = qgetenv("TZ");   // save the original local time zone
     qputenv("TZ", tzfile.toLatin1());
     ::tzset();