(PA-6764) Add MacOS 15 ARM to the install-puppet script

.github/workflows/install_puppet.yaml

@@ -6,8 +6,6 @@ on:
   pull_request:
     branches: [ main ]
 
-# Even though checkout@v3 is end-of-life, we cannot upgrade to v4
-# because it cannot run on CentOS 7 and Ubuntu 18.04
 jobs:
   install-puppet:
     name: ${{ matrix.collection }} / ${{ matrix.os.name }}
@@ -17,19 +15,17 @@ jobs:
       matrix:
         collection: [ puppet7, puppet8 ]
         os: [
-          { name: "CentOS 7", image: "litmusimage/centos:7" },
           { name: "Debian 10", image: "litmusimage/debian:10" },
           { name: "Debian 11", image: "litmusimage/debian:11" },
           { name: "Debian 12", image: "litmusimage/debian:12" },
-          { name: "Ubuntu 18.04", image: "litmusimage/ubuntu:18.04" },
           { name: "Ubuntu 20.04", image: "litmusimage/ubuntu:20.04" },
           { name: "Ubuntu 22.04", image: "litmusimage/ubuntu:22.04" },
         ]
     container:
       image: ${{ matrix.os.image }}
     steps:
       - name: Checkout current PR
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           fetch-depth: 0
       - name: Install puppet-agent from ${{ matrix.collection }} collection

install.sh

@@ -364,7 +364,7 @@ if [ -n "$PT_mac_source" ]; then
   mac_source=$PT_mac_source
 else
   if [ "$nightly" = true ]; then
-    mac_source='http://nightlies.puppet.com/downloads'
+    mac_source='https://artifactory.delivery.puppetlabs.net:443/artifactory/internal_nightly__local/downloads'
   else
     mac_source='http://downloads.puppet.com'
   fi
@@ -481,6 +481,7 @@ if true; then
       "12")    platform_version="12";;
       "13")    platform_version="13";;
       "14")    platform_version="14";;
+      "15")    platform_version="15";;
       *) echo "No builds for platform: $major_version"
          exit 1
          ;;