Use pipx install since upgrade doesn't work on first install

Maybe should add --force to allow upgrades, but keeping it stable for now.

install-coding-helpers.sh

@@ -93,7 +93,7 @@ function maybe_pip_install() {
 
     if command_exists pipx ;then
         # Prefer pipx to keep environments isolated
-        pipx upgrade "${user_bins[@]}"
+        pipx install "${user_bins[@]}"
     else
         if command_exists pip3 ;then
             # If pip3 is there, use it to ensure we're using python 3