development/rust: don't modify the path

In the automated install, the default is to automatically append to
the user's profile file. I already have a check in my profile, and
I don't want to duplicate this.

roles/development/tasks/main.yml

@@ -238,7 +238,7 @@
 
 - name: install rust/cargo
   when: (dev_rust or dev_full) and (cargo_exists is failed)
-  shell: /tmp/sh.rustup.rs -y
+  shell: /tmp/sh.rustup.rs -y --no-modify-path
 
 
 ## AI/ML stuff