cleanup: trim trailing whitespace (#11136)

* cleanup: trim trailing whitespace

* update(`.editorconfig`)

---------

Co-authored-by: syuilo <Syuilotan@yahoo.co.jp>

packages/backend/test/prelude/get-api-validator.ts

@@ -5,7 +5,7 @@ export const getValidator = (paramDef: Schema) => {
     const ajv = new Ajv({
         useDefaults: true,
     });
-    ajv.addFormat('misskey:id', /^[a-zA-Z0-9]+$/);		
+    ajv.addFormat('misskey:id', /^[a-zA-Z0-9]+$/);
 
     return ajv.compile(paramDef);
 }