upgrade alpine base image from v3.17.3 to v3.18.0 including upgrade of postfix package from v3.7.4-r0 to v3.8.0-r1 (support for dns srv lookup; tls obsolescence; removes redis support; see below)

https://web.archive.org/web/20230514092759/https://www.postfix.org/announcements/postfix-3.8.0.html
https://web.archive.org/web/20230514092849/https://git.alpinelinux.org/aports/commit/main/postfix?h=3.18-stable&id=78821a79345d7cc00d8560de19ddc1d5982bb778
https://web.archive.org/web/20230514092943/https://git.alpinelinux.org/aports/commit/main/postfix?h=3.18-stable&id=f16034e090766087f31612f5851c2f74a7bca332
https://web.archive.org/web/20230514093049/https://git.alpinelinux.org/aports/commit/main/postfix?h=3.18-stable&id=3fa68c7d72ac6d5f6bf03a4e43bce5c4b3434ff6

Dockerfile

@@ -1,6 +1,8 @@
-FROM alpine:3.17.3
+FROM docker.io/alpine:3.18.0
 
-ARG POSTFIX_PACKAGE_VERSION=3.7.4-r0
+# http://www.postfix.org/announcements.html
+# https://git.alpinelinux.org/aports/log/main/postfix?h=3.18-stable
+ARG POSTFIX_PACKAGE_VERSION=3.8.0-r1
 # http://www.postfix.org/postconf.5.html#tls_append_default_CA
 # https://www.mozilla.org/en-US/about/governance/policies/security-group/certs/
 # https://gitlab.alpinelinux.org/alpine/ca-certificates/-/commits/master

postfix-package-log.url

@@ -1 +0,0 @@
-https://git.alpinelinux.org/aports/log/main/postfix?h=3.17-stable

postfix-release-notes.url

@@ -1 +0,0 @@
-http://www.postfix.org/announcements.html