fix: several CI errors (#8124)

* Revert "build(cmake): support building with (almost) all system 3rd-party libraries (#7554)"

This reverts commit a89ca4f2c9.

* fixup! refactor: use a map of getters, setters for `session_get` and `session_set` properties (#8024)

fix: capture-by-reference error in session_accessors()

* fix: 'Qt depends on a UTF-8 locale' CI warning

* fix: 'qt.qpa.xcb: could not connect to display' CI error

utils/CMakeLists.txt

@@ -10,7 +10,7 @@ foreach(P create edit remote show)
             ${TR_NAME}
             CURL::libcurl
             fmt::fmt-header-only
-            libevent::core)
+            libevent::event)
 
     tr_win32_app_info(${TR_NAME}-${P}
         "Transmission Utility ('${P}')"