feat!: removes Node.js 18 as it reached EOL (#742)

Author: timbru31

.github/workflows/buildx.yml

@@ -15,7 +15,7 @@ jobs:
       fail-fast: false
       matrix:
         ruby-version: [3.2, 3.3, 3.4]
-        node-version: [18, 20, 22]
+        node-version: [20, 22]
         variant: [default, slim, alpine]
         include:
           - variant: default
@@ -32,7 +32,6 @@ jobs:
         id: nodename
         run: |
           case "${{ matrix.node-version }}" in
-            "18") echo "codename=hydrogen" >> $GITHUB_OUTPUT ;;
             "20") echo "codename=iron" >> $GITHUB_OUTPUT ;;
             "22") echo "codename=jod" >> $GITHUB_OUTPUT ;;
             "24") echo "codename=krypton" >> $GITHUB_OUTPUT ;;

.github/workflows/dockerimage.yml

@@ -14,7 +14,7 @@ jobs:
       fail-fast: false
       matrix:
         ruby-version: [3.2, 3.3, 3.4]
-        node-version: [18, 20, 22]
+        node-version: [20, 22]
         variant: [default, slim, alpine]
 
     steps:

3.2/18/Dockerfile

@@ -1,15 +1,15 @@
-# Ruby 3.2, 3.3 or 3.4 with Node.js 18 LTS, Node.js 20 LTS or Node.js 22 Dockerfile
+# Ruby 3.2, 3.3 or 3.4 with Node.js 20 LTS or Node.js 22 Dockerfile
 
 [![Docker Automated build](https://img.shields.io/docker/automated/timbru31/ruby-node.svg)](https://hub.docker.com/r/timbru31/ruby-node/)
 [![buildx Status](https://github.com/timbru31/docker-ruby-node/workflows/buildx/badge.svg)](https://github.com/timbru31/docker-ruby-node/actions?query=workflow%3Abuildx)
 [![Lint Dockerfiles](https://github.com/timbru31/docker-ruby-node/workflows/Lint%20Dockerfiles/badge.svg)](https://github.com/timbru31/docker-ruby-node/actions?query=workflow%3A%22Lint+Dockerfiles%22)
 
-A minimal Dockerfile based on Ruby (3.2, 3.3 or 3.4) Dockerfile (regular, slim or alpine) with Node.js 18 LTS (Hydrogen), Node.js 20 LTS (Iron) or Node.js 22 LTS (Jod) installed.
+A minimal Dockerfile based on Ruby (3.2, 3.3 or 3.4) Dockerfile (regular, slim or alpine) with Node.js 20 LTS (Iron) or Node.js 22 LTS (Jod) installed.
 
 ## What's included
 
 - Ruby 3.2, 3.3, 3.4
-- Node.js 18 LTS (Hydrogen), Node.js 20 LTS (Iron) or Node.js 22 LTS (Jod)
+- Node.js 20 LTS (Iron) or Node.js 22 LTS (Jod)
 - bundled npm that comes with the respective Node.js version (latest for Node.js LTS on alpine, see [why](https://gitlab.alpinelinux.org/alpine/aports/-/commit/25b10bd1a93e12a7e49fee38b0a229281ae49fb7))
 - yarn