[ui] Fix case sensitivity in launchpad partition picker (#23916)

## Summary & Motivation

I noticed that on one of my assets with string partition names,
searching for the partition in the asset launchpad is case-sensitive. It
shouldn't be.

## How I Tested These Changes

View asset with named partitions, open launchpad. Search for a
partition, verify that it appears regardless of query case.

## Changelog [New | Bug | Docs]

[ui] Fix case sensitivity when searching for partitions in the
launchpad.

js_modules/dagster-ui/packages/ui-core/src/launchpad/ConfigEditorConfigPicker.tsx

@@ -304,7 +304,10 @@ const ConfigEditorPartitionPicker = React.memo((props: ConfigEditorPartitionPick
         items={partitions}
         inputProps={inputProps}
         inputValueRenderer={(partition) => partition}
-        itemPredicate={(query, partition) => query.length === 0 || partition.includes(query)}
+        itemPredicate={(query, partition) => {
+          const sanitized = query.trim().toLocaleLowerCase();
+          return sanitized.length === 0 || partition.toLocaleLowerCase().includes(sanitized);
+        }}
         itemRenderer={(partition, props) => (
           <MenuItem
             active={props.modifiers.active}