add archlinux installation methods

tasks/pkgs/zig.yml

@@ -8,12 +8,21 @@
 ---
 - name: Set zig default facts
   ansible.builtin.set_fact:
-    methods:
-      - archive
-      - system
-    version: "{{ zig_version | default('0.15.2') }}"
-    archive:
-      url: https://ziglang.org/download
+    zig:
+      methods:
+        default: [archive]
+        Archlinux: [system, archive]
+      pkgname:
+        default: zig
+
+- name: Finalise zig default facts
+  ansible.builtin.set_fact:
+    zig:
+      methods: "{{ zig.methods[os_family] | default(zig.methods.default) }}"
+      pkgname: "{{ zig.pkgname[os_family] | default(zig.pkgname.default) }}"
+      version: "{{ zig_version | default('0.15.2') }}"
+      archive:
+        url: https://ziglang.org/download
 
 - name: Configure zig
   when:
@@ -29,7 +38,8 @@
       when:
         - zig_imethod == 'system'
       ansible.builtin.set_fact:
-        pkg_sys: "{{ pkg_sys + [zig.pkgname[os_family]] }}"
+        pkg_sys: "{{ pkg_sys + [zig.pkgname] }}"
+        zig_install: "{{ zig_imethod }}={{ zig.pkgname }}"
 
     - name: Configure zig archive install
       when: