use Node.js 18 instead of Node.js 14 in Dockerfile

The previously used Node.js 14 is an old LTS version that has
reached its end of support in 2023, so it should no longer be
used.

Dockerfile

@@ -19,9 +19,9 @@ RUN apt-get update && apt-get upgrade -y && \
  ca-certificates \
  libfontconfig1
 # Node.js is required to run this application.
-RUN echo "# Node.js 14.x for Debian 11 (codename bullseye)" > /etc/apt/sources.list.d/nodejs.list \
- && echo "deb https://deb.nodesource.com/node_14.x bullseye main" >> /etc/apt/sources.list.d/nodejs.list \
- && echo "deb-src https://deb.nodesource.com/node_14.x bullseye main" >> /etc/apt/sources.list.d/nodejs.list
+RUN echo "# Node.js 18.x for Debian 11 (codename bullseye)" > /etc/apt/sources.list.d/nodejs.list \
+ && echo "deb https://deb.nodesource.com/node_18.x bullseye main" >> /etc/apt/sources.list.d/nodejs.list \
+ && echo "deb-src https://deb.nodesource.com/node_18.x bullseye main" >> /etc/apt/sources.list.d/nodejs.list
 RUN apt-key adv --fetch-keys https://deb.nodesource.com/gpgkey/nodesource.gpg.key
 RUN apt-get update && apt-get install --no-install-recommends -y nodejs
 # Create directory for application.

changelog.md

@@ -10,6 +10,11 @@ Since [ECharts](https://echarts.apache.org/) is the main dependency of this
 application, major version changes in ECharts will also trigger a major version
 change in this application.
 
+## Version 5.?.? (2024-05-??)
+
+* __[maintenance]__
+Update Dockerfile to use Node.js 18 instead of Node.js 14.
+
 ## Version 5.1.2 (2024-03-31)
 
 * __[maintenance]__