feat: add cargo-update for keeping cargo tools current

Installs cargo-update crate which provides `cargo install-update -a`
to update all cargo-installed binaries to latest versions.

Author: Derek

ansible/roles/developer_core/tasks/rust.yml

@@ -189,3 +189,16 @@
   environment: "{{ cargo_env }}"
   become: "{{ ansible_facts['distribution'] != 'MacOSX' }}"
   become_user: "{{ actual_user if ansible_facts['distribution'] != 'MacOSX' else omit }}"
+
+# ============================================================
+# cargo-update: allows manual `cargo install-update -a` to
+# update all cargo-installed tools to latest versions
+# ============================================================
+
+- name: Install cargo-update (for updating cargo tools)
+  ansible.builtin.command:
+    cmd: cargo install cargo-update
+    creates: "{{ user_home }}/.cargo/bin/cargo-install-update"
+  environment: "{{ cargo_env }}"
+  become: "{{ ansible_facts['distribution'] != 'MacOSX' }}"
+  become_user: "{{ actual_user if ansible_facts['distribution'] != 'MacOSX' else omit }}"