bump up rootlesskit to v0.14.4

Fixes `panic: tap2vif: read: read /dev/net/tun: not pollable` on early
start up of RootlessKit with VPNKit.

Changes:
- https://github.com/rootless-containers/rootlesskit/releases/tag/v0.14.4
- https://github.com/rootless-containers/rootlesskit/releases/tag/v0.14.3

Signed-off-by: Akihiro Suda <akihiro.suda.cz@hco.ntt.co.jp>
(cherry picked from commit 9499acc36092929d4737df5f1a64c36662bed39b)
Signed-off-by: Akihiro Suda <akihiro.suda.cz@hco.ntt.co.jp>

hack/dockerfile/install/rootlesskit.installer

@@ -1,7 +1,7 @@
 #!/bin/sh
 
-# v0.14.2
-: "${ROOTLESSKIT_COMMIT:=4cd567642273d369adaadcbadca00880552c1778}"
+# v0.14.4
+: "${ROOTLESSKIT_COMMIT:=87d443683ac1e8aba4110b8081f15aaae432aaa2}"
 
 install_rootlesskit() {
 	case "$1" in