Use https for postgres repo

Suggested by Copilot, I don't think it is more secure as it already is key verified.

Author: zetter-rpf

Dockerfile

@@ -7,7 +7,7 @@ RUN gem install bundler \
   curl gnupg graphviz nodejs \
   && mkdir -p /usr/share/keyrings \
   && curl -fsSL https://www.postgresql.org/media/keys/ACCC4CF8.asc | gpg --dearmor -o /usr/share/keyrings/postgresql-archive-keyring.gpg \
-  && echo "deb [signed-by=/usr/share/keyrings/postgresql-archive-keyring.gpg] http://apt.postgresql.org/pub/repos/apt trixie-pgdg main" > /etc/apt/sources.list.d/pgdg.list \
+  && echo "deb [signed-by=/usr/share/keyrings/postgresql-archive-keyring.gpg] https://apt.postgresql.org/pub/repos/apt trixie-pgdg main" > /etc/apt/sources.list.d/pgdg.list \
   && apt-get update \
   && apt-get install --yes --no-install-recommends postgresql-client-17 \
   && rm -rf /var/lib/apt/lists/* /var/lib/apt/archives/*.deb