fix: Add Alpine 3.21 to Agent workflow

Author: alessfg

molecule/agent/molecule.yml

@@ -42,6 +42,14 @@ platforms:
     volumes:
       - /sys/fs/cgroup:/sys/fs/cgroup:rw
     command: /sbin/init
+  - name: alpine-3.21
+    image: alpine:3.21
+    dockerfile: ../common/Dockerfile.j2
+    privileged: true
+    cgroupns_mode: host
+    volumes:
+      - /sys/fs/cgroup:/sys/fs/cgroup:rw
+    command: /sbin/init
   - name: amazonlinux-2
     image: amazonlinux:2
     platform: x86_64