bump up rootlesskit from v0.14.4 to v0.14.6

Minor fixes and refactoring.
https://github.com/rootless-containers/rootlesskit/compare/v0.14.4...v0.14.6

Signed-off-by: Akihiro Suda <akihiro.suda.cz@hco.ntt.co.jp>

hack/dockerfile/install/rootlesskit.installer

@@ -1,6 +1,6 @@
 #!/bin/sh
 
-: "${ROOTLESSKIT_VERSION:=v0.14.4}"
+: "${ROOTLESSKIT_VERSION:=v0.14.6}"
 
 install_rootlesskit() {
 	case "$1" in