remove deprecated use of IFS

pkg/omf/functions/cli/omf.cli.help.fish

 function omf.cli.help
-  set -l IFS ''
   set -l doc_root $OMF_PATH/docs/cli
   set -l doc $doc_root/omf.adoc
 

pkg/omf/functions/core/omf.doctor.fish

@@ -16,8 +16,7 @@ function __omf.doctor.fish_version
   set -l min_version 2.2.0
   set -l current_version
   begin
-    set -l IFS '-'
-    echo $FISH_VERSION | read -la version_parts
+    echo $FISH_VERSION | read -la --delimiter - version_parts
     set current_version "$version_parts[1]"
   end
 

pkg/omf/functions/index/omf.index.query.fish

@@ -13,11 +13,9 @@ function omf.index.query -d 'Query packages in the index'
       case '--type=theme'
         set q_type theme
       case '--name=*'
-        set -l IFS '='
-        echo "$arg" | read dummy q_name
+        echo "$arg" | read --delimiter = dummy q_name
       case '--text=*'
-        set -l IFS '='
-        echo "$arg" | read dummy q_text
+        echo "$arg" | read --delimiter = dummy q_text
       case '*'
         echo "Invalid search term: '$arg'" >&2
         return 1