rootless: update test version to 29.0.0-rc.2 #640

Job	Run time
test-install-rootless	10s
test (ubuntu:24.04)	1m 19s
test (ubuntu:22.04, 27.5)	3m 13s
test (quay.io/centos/centos:stream9)	1m 59s
test (ubuntu:24.04, 27.5)	2m 53s
test (quay.io/centos/centos:stream9, 27.5)	1m 39s
test (ubuntu:22.04)	1m 41s
	12m 54s

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