Continued Github Actions(CI) execution after CentOS 7 EOL

.github/workflows/ci.yml

@@ -61,6 +61,7 @@ jobs:
           - fedora:39
           - opensuse/leap:15
           - alpine:3.20
+          - centos:centos7
 
     container:
       image: ${{ matrix.container }}
@@ -71,6 +72,12 @@ jobs:
       # Installation special environment variables for debian and ubuntu.
       #
       DEBIAN_FRONTEND:  noninteractive
+      # [NOTE]
+      # actions/checkout uses node20, but can only run up to node16 on centos7.
+      # (glibc 2.27 or later is required to use node20)
+      # This is a temporary solution and will be removed when centos7 support is discontinued.
+      #
+      ACTIONS_ALLOW_USE_UNSECURE_NODE_VERSION: ${{ matrix.container == 'centos:centos7' && true || false }}
 
     steps:
       # [NOTE]
@@ -82,9 +89,8 @@ jobs:
           zypper install -y tar gzip
 
       # [NOTE]
-      # actions/checkout@v3 uses nodejs v16 and will be deprecated.
-      # However, @v4 does not work on centos7 depending on the glibc version,
-      # so we will continue to use @v3.
+      # Use actions/checkout@v4 except for centos7.
+      # On centos7, we need to run actions/checkout@v3 and configure it to use node16.
       #
       - name: Checkout source code(other than centos7)
         if: matrix.container != 'centos:centos7'