upgrade openvpn package from v2.6.4-r0 to v2.6.5-r0

https://github.com/OpenVPN/openvpn/blob/v2.6.5/Changes.rst
https://git.alpinelinux.org/aports/commit/main/openvpn?h=3.18-stable&id=9b3ea3fb82452dc160a6f51934c3082c7c6da2fe

Dockerfile

@@ -1,7 +1,8 @@
 FROM docker.io/alpine:3.18.0
 
+# https://github.com/OpenVPN/openvpn/blob/master/Changes.rst
 # https://git.alpinelinux.org/aports/log/main/openvpn?h=3.18-stable
-ARG OPENVPN_PACKAGE_VERSION=2.6.4-r0
+ARG OPENVPN_PACKAGE_VERSION=2.6.5-r0
 RUN apk add --no-cache openvpn=$OPENVPN_PACKAGE_VERSION
 
 VOLUME /vpn-config