[Docker] Explicitly use new alpine version

Alpine 3.17 has jemalloc back in it's repositories, which means it can just
be installed through the package manager.
Also explicitly install postgres 12 packages. That was already possible with
alpine 3.16 but I didn't know about it back then.

.ruby-version

@@ -1 +1 @@
-3.1.2
+3.1.3

Dockerfile

@@ -1,18 +1,13 @@
-FROM ruby:3.1.2-alpine
+FROM ruby:3.1.3-alpine3.17
 
 # Dependencies for setup and runtime
-RUN apk --no-cache add nodejs yarn postgresql-client ffmpeg vips tzdata \
-  git build-base postgresql-dev glib-dev bash
-
-RUN wget -O - https://github.com/jemalloc/jemalloc/releases/download/5.2.1/jemalloc-5.2.1.tar.bz2 | tar -xj && \
-    cd jemalloc-5.2.1 && \
-    ./configure && \
-    make && \
-    make install
+RUN apk --no-cache add nodejs yarn ffmpeg vips \
+  postgresql12-client postgresql12-dev \
+  bash build-base git glib-dev jemalloc tzdata
 
 RUN git config --global --add safe.directory /app
 
-ENV LD_PRELOAD=/usr/local/lib/libjemalloc.so.2
+ENV LD_PRELOAD=/usr/lib/libjemalloc.so.2
 
 # Install js packages and gems
 COPY package.json yarn.lock ./