Add 29.5.0-rc.1, drop vpnkit for 29.5+

[yosifkit]

vpnkit is no longer included in the docker-rootless-extras-*.tgz and is no longer necessary for RootlessKit 3.0.0: moby/moby#52319

Since it is no longer included, the automated update job cannot successfully build the 29.5.0-rc.1 release:

+ wget -O rootless.tgz https://download.docker.com/linux/static/test/x86_64/docker-rootless-extras-29.5.0-rc.1.tgz
...
+ tar --extract --file rootless.tgz --strip-components 1 --directory /usr/local/bin/ docker-rootless-extras/rootlesskit docker-rootless-extras/vpnkit
tar: docker-rootless-extras/vpnkit: not found in archive