Fix overloaded argparse keys (#27379)

Commands should not reuse option names defined in main.

share/spack/spack-completion.bash

@@ -969,12 +969,7 @@ _spack_env_st() {
 }
 
 _spack_env_loads() {
-    if $list_options
-    then
-        SPACK_COMPREPLY="-h --help -n --module-set-name -m --module-type --input-only -p --prefix -x --exclude -r --dependencies"
-    else
-        _environments
-    fi
+    SPACK_COMPREPLY="-h --help -n --module-set-name -m --module-type --input-only -p --prefix -x --exclude -r --dependencies"
 }
 
 _spack_env_view() {