👕 #347 以下のESLintの警告に対応

/lgtm-cat-frontend/src/app/_components/Header.test.tsx
  31:51  warning  Use shorthand boolean attribute 'isLoggedIn'  react/prefer-shorthand-boolean
  42:51  warning  Use shorthand boolean attribute 'isLoggedIn'  react/prefer-shorthand-boolean

/lgtm-cat-frontend/src/app/_components/HeaderLogo.tsx
  21:41  warning  Use shorthand boolean attribute 'aria-hidden'  react/prefer-shorthand-boolean

/lgtm-cat-frontend/src/app/_components/LoginButton.tsx
  14:7  warning  Use shorthand boolean attribute 'showGithubIcon'  react/prefer-shorthand-boolean

src/app/_components/Footer.test.tsx

@@ -1,5 +1,5 @@
 import { render, screen } from '@testing-library/react';
-import { expect } from 'vitest';
+import { expect, it } from 'vitest';
 import { Footer } from './Footer';
 import '@testing-library/jest-dom';
 

src/app/_components/Header.test.tsx

@@ -1,5 +1,5 @@
 import { render, screen } from '@testing-library/react';
-import { expect } from 'vitest';
+import { expect, it } from 'vitest';
 import { Header } from './Header';
 import '@testing-library/jest-dom';
 
@@ -28,6 +28,7 @@ it('show isLoggedIn false language is en', () => {
 });
 
 it('show isLoggedIn true language is ja', () => {
+  // eslint-disable-next-line react/prefer-shorthand-boolean
   render(<Header language="ja" currentUrlPath="/" isLoggedIn={true} />);
 
   expect(screen.getByRole('link', { name: 'LGTMeow' })).toBeTruthy();
@@ -39,6 +40,7 @@ it('show isLoggedIn true language is ja', () => {
 });
 
 it('show isLoggedIn true language is en', () => {
+  // eslint-disable-next-line react/prefer-shorthand-boolean
   render(<Header language="en" currentUrlPath="/" isLoggedIn={true} />);
 
   expect(screen.getByRole('link', { name: 'LGTMeow' })).toBeTruthy();

src/app/_components/HeaderLogo.tsx

@@ -18,6 +18,7 @@ export function HeaderLogo({ language }: Props): JSX.Element {
       className="flex h-10 w-[218px] items-center justify-center gap-0.5 bg-orange-500"
       prefetch={false}
     >
+      {/* eslint-disable-next-line react/prefer-shorthand-boolean */}
       <LgtmCatIcon className="shrink-0" aria-hidden={true} />
       <h1 className="text-4xl font-bold text-orange-50 no-underline">
         <Text>LGTMeow</Text>

src/app/_components/LoginButton.tsx

@@ -11,6 +11,7 @@ export function LoginButton({ language }: Props): JSX.Element {
   return (
     <IconButton
       displayText={language === 'en' ? 'Login' : 'ログイン'}
+      // eslint-disable-next-line react/prefer-shorthand-boolean
       showGithubIcon={true}
       link={createIncludeLanguageAppPath('login', language)}
     />