upgrade alpine base image from v3.20.3 to v3.21.0 including upgrade of postfix & ca-certificates package

https://www.postfix.org/announcements/postfix-3.9.1.html
https://git.alpinelinux.org/aports/commit/main/postfix?h=3.20-stable&id=068b58b02cb5a2c89cfe47352493249b51d1b58d

https://git.alpinelinux.org/aports/commit/main/ca-certificates?h=3.21-stable&id=537f890454d2213fd05cde5e458dfa9c8ef1977f

Dockerfile

@@ -6,16 +6,16 @@
 #
 # SPDX-License-Identifier: EPL-2.0
 
-FROM docker.io/alpine:3.20.3
+FROM docker.io/alpine:3.21.0
 
 # http://www.postfix.org/announcements.html
-# https://git.alpinelinux.org/aports/log/main/postfix?h=3.20-stable
-ARG POSTFIX_PACKAGE_VERSION=3.9.0-r1
+# https://git.alpinelinux.org/aports/log/main/postfix?h=3.21-stable
+ARG POSTFIX_PACKAGE_VERSION=3.9.1-r0
 # 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
-# https://git.alpinelinux.org/aports/log/main/ca-certificates?h=3.19-stable
-ARG MOZILLA_CA_CERT_STORE_PACKAGE_VERSION=20240705-r0
+# https://git.alpinelinux.org/aports/log/main/ca-certificates?h=3.21-stable
+ARG MOZILLA_CA_CERT_STORE_PACKAGE_VERSION=20241010-r0
 RUN apk add --no-cache \
         ca-certificates=$MOZILLA_CA_CERT_STORE_PACKAGE_VERSION \
         postfix=$POSTFIX_PACKAGE_VERSION \