A few updates.

- Update to Alpine 3.18.
- Update to Ruby 3.2.
- Update transmission-rss to 1.2.3.

daemon/Dockerfile

-FROM alpine:3.16
+FROM alpine:3.18
 # hadolint ignore=DL3018
 RUN apk add --update --no-cache --repository http://dl-cdn.alpinelinux.org/alpine/edge/testing/ \
         gosu \

rss/Dockerfile

-FROM docker.io/library/ruby:3.1-slim
+FROM docker.io/library/ruby:3.2-slim
 # hadolint ignore=DL3008
 RUN apt-get update && \
     DEBIAN_FRONTEND=noninteractive apt-get install -y --no-install-recommends \
@@ -6,7 +6,7 @@ RUN apt-get update && \
         gosu \
     && \
     gem install \
-        transmission-rss:1.2.2 \
+        transmission-rss:1.2.3 \
     && \
     DEBIAN_FRONTEND=noninteractive apt-get purge -y --auto-remove \
         build-essential \