tools: ynl: produce kselftest-list.txt from tests

Executors will need kselftest-list.txt so create it when
tests are installed.

Acked-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Reviewed-by: Hangbin Liu <liuhangbin@gmail.com>
Reviewed-by: Donald Hunter <donald.hunter@gmail.com>
Link: https://patch.msgid.link/20260303163504.2084981-5-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

tools/net/ynl/tests/Makefile

@@ -26,6 +26,9 @@ install: $(TEST_PROGS)
 		    $$test > $(INSTALL_PATH)/ynl/$$name; \
 		chmod +x $(INSTALL_PATH)/ynl/$$name; \
 	done
+	@for test in $(TEST_PROGS); do \
+		echo "ynl:$$test"; \
+	done > $(INSTALL_PATH)/kselftest-list.txt
 
 clean distclean:
 	@# Nothing to clean