[GR-59964] Fix checkcopyright in sulong style gate. #20166

Job	Run time
/substratevm on Windows	8m 57s
/compiler style,fullbuild,test JDK21	29m 27s
/compiler build,bootstraplite JDKlatest	4m 38s
/espresso style,fullbuild JDK21	12m 54s
/substratevm style,fullbuild JDK21	11m 19s
/substratevm build,helloworld,native_unittests JDKlatest	20m 14s
/substratevm build,debuginfotest JDKlatest	23m 2s
/substratevm hellomodule JDKlatest	5m 2s
/sulong style,fullbuild,sulongBasic JDK21	20m 4s
/truffle JDK21	30m 52s
/vm build,sulong JDKlatest	26m 38s
/vm build JDKlatest	15m 34s
	3h 28m 41s

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