Fix eslint warnings

Signed-off-by: Thomas Citharel <tcit@tcit.fr>

js/src/utils/validators.ts

@@ -1,7 +1,7 @@
-export function validateEmailField(value: string) {
+export function validateEmailField(value: string): boolean | string {
   return value.includes("@") || "Invalid e-mail.";
 }
 
-export function validateRequiredField(value: any) {
+export function validateRequiredField(value: unknown): boolean | string {
   return !!value || "Required.";
 }