Remove unnecessary loading of qt.cfg in testtokenize.cpp #19142

Job	Run time
build_make (ubuntu:25.10)	3m 39s
build_make (alpine:3.23)	6m 8s
build_cmake (ubuntu:25.10, true, true)	2m 53s
build_cmake (ubuntu:24.04, true, true)	2m 47s
build_make (ubuntu:24.04)	3m 6s
build_cmake (alpine:3.23, false, false)	4m 36s
	23m 9s

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