Fix rustup-init failing on fresh systems

~/.cargo/env does not exist before rustup-init runs — sourcing it
upfront caused the task to fail on clean installs. Switch to a plain
command invocation without the premature source.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

ansible/roles/profile_desktop_common/tasks/main.yml

@@ -472,9 +472,9 @@
         path: "{{ user_home }}/.cargo/bin/rustc"
       register: rustup_initialized
 
-    - name: Run rustup-init with cargo env sourced
-      ansible.builtin.shell:
-        cmd: . ~/.cargo/env && rustup-init -y --no-modify-path
+    - name: Run rustup-init
+      ansible.builtin.command:
+        cmd: rustup-init -y --no-modify-path
         creates: "{{ user_home }}/.cargo/bin/rustc"
       become_user: "{{ username }}"
       environment: