Fix #14880 add support for Folders in slnx project file and skip non … #20410

Job	Run time
build_cmake (ubuntu:24.04, true, true)	5m 36s
build_make (ubuntu:25.10)	2m 42s
build_cmake (ubuntu:25.10, true, true)	3m 32s
build_make (alpine:3.23)	5m 58s
build_cmake (alpine:3.23, false, false)	4m 31s
build_make (ubuntu:24.04)	2m 54s
	25m 13s

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