Automatically remove the min_columns property.

src/config-mgmt.ts

@@ -174,6 +174,12 @@ const createRangedTransform = function (
   };
 };
 
+/**
+ * Convert a value from 'XXpx' to XX (as a number).
+ * @param value Incoming value.
+ * @returns A number, null if the property should be deleted or undefined if it
+ * should be ignored.
+ */
 const toPixelsOrDelete = function (value: unknown): number | null | undefined {
   // Ignore the value if it's a number.
   if (typeof value === 'number') {
@@ -189,6 +195,16 @@ const toPixelsOrDelete = function (value: unknown): number | null | undefined {
   return isNaN(value as number) ? null : Number(value);
 };
 
+/**
+ * Request a property be deleted.
+ * @param _value Inbound value (not required).
+ * @returns `null` to request the property be deleted.
+ */
+// eslint-disable-next-line @typescript-eslint/no-unused-vars
+const deleteProperty = function (_value: unknown): number | null | undefined {
+  return null;
+}
+
 /**
  * Move a property from one location to another.
  * @param obj The configuration object in which the property resides.
@@ -445,4 +461,8 @@ const UPGRADES = [
     CONF_MENU_BUTTON_SIZE,
     createRangedTransform(toPixelsOrDelete, BUTTON_SIZE_MIN),
   ),
+  upgradeWithOverrides(
+    'event_gallery.min_columns',
+    deleteProperty
+  ),
 ];