fix: revert sizing plugin forColumns

None of this logic was previously working, because the feature 'columnResizing'
that was added in commit: 7a09878 and being
used to lookup the plugin was incorrect.
Since we were always getting back the table.columns.values, we can revert this
unused logic.

ember-headless-table/src/plugins/-private/base.ts

@@ -289,7 +289,6 @@ function columnsFor<DataType = any>(
 
   let visibility = findPlugin(table.plugins, 'columnVisibility');
   let reordering = findPlugin(table.plugins, 'columnOrder');
-  let sizing = findPlugin(table.plugins, 'columnResizing');
 
   // TODO: actually resolve the graph, rather than use the hardcoded feature names
   //       atm, this only "happens" to work based on expectations of
@@ -302,10 +301,6 @@ function columnsFor<DataType = any>(
       table.plugins.some((plugin) => plugin instanceof (requester as Class<Plugin>))
     );
 
-    if (sizing && sizing.constructor === requester) {
-      return table.columns.values();
-    }
-
     if (visibility && visibility.constructor === requester) {
       return table.columns.values();
     }
@@ -341,15 +336,6 @@ function columnsFor<DataType = any>(
       return visibility.columns;
     }
 
-    if (sizing) {
-      assert(
-        `<#${sizing.name}> defined a 'columns' property, but did not return valid data.`,
-        sizing.columns && Array.isArray(sizing.columns)
-      );
-
-      return sizing.columns;
-    }
-
     return table.columns.values();
   }
 
@@ -375,15 +361,6 @@ function columnsFor<DataType = any>(
     return visibility.columns;
   }
 
-  if (sizing) {
-    assert(
-      `<#${sizing.name}> defined a 'columns' property, but did not return valid data.`,
-      sizing.columns && Array.isArray(sizing.columns)
-    );
-
-    return sizing.columns;
-  }
-
   return table.columns.values();
 }