misc(version): Bump version to 1.31.0 (#68)

Author: vincent-pochet

scripts/build_npm.ts

@@ -32,7 +32,7 @@ await build({
     // package.json properties
     name: "lago-javascript-client",
     sideEffects: false,
-    version: "v1.30.0",
+    version: "v1.31.0",
     description: "Lago JavaScript API Client",
     repository: {
       type: "git",