Fix linter issues

moneymgr_web/src/widgets/forms/UploadFileButton.tsx

@@ -1,8 +1,8 @@
-import { Button, IconButton, Tooltip, Typography } from "@mui/material";
 import UploadFileIcon from "@mui/icons-material/UploadFile";
-import { ServerApi } from "../../api/ServerApi";
+import { Button, Tooltip, Typography } from "@mui/material";
 import React from "react";
 import { FileApi, UploadedFile } from "../../api/FileApi";
+import { ServerApi } from "../../api/ServerApi";
 import { useAlert } from "../../hooks/context_providers/AlertDialogProvider";
 import { useLoadingMessage } from "../../hooks/context_providers/LoadingMessageProvider";
 import { useSnackbar } from "../../hooks/context_providers/SnackbarProvider";
@@ -58,7 +58,7 @@ export function UploadFileButton(p: {
   const handlefileChange = (ev: React.ChangeEvent) => {
     ev.preventDefault();
     if ((fileInput.current?.files?.length ?? 0) > 0) {
-      handleUpload([...fileInput.current?.files!]);
+      handleUpload([...fileInput.current!.files!]);
     }
   };
 
@@ -66,7 +66,9 @@ export function UploadFileButton(p: {
     <Tooltip
       title={p.tooltip}
       onDrop={handleDrop}
-      onDragOver={(event) => event.preventDefault()}
+      onDragOver={(event) => {
+        event.preventDefault();
+      }}
       onDragEnter={dragEnter}
       onDragLeave={dragLeave}
     >