Remove old browser (headless) tests (#37433)

Author: Peter Bengtsson

.github/workflows/browser-test.yml

@@ -1,6 +1,5 @@
 // https://jestjs.io/docs/en/configuration.html
 
-const isBrowser = process.env.BROWSER
 const isActions = Boolean(process.env.GITHUB_ACTIONS)
 
 const reporters = ['default']
@@ -18,22 +17,20 @@ export default {
       statements: -5,
     },
   },
-  preset: isBrowser ? 'jest-puppeteer' : undefined,
   moduleNameMapper: {
     // fix for "Unexpected token 'export'" error when running jest
     '@primer/behaviors': '<rootDir>/node_modules/@primer/behaviors/dist/cjs/index.js',
   },
   reporters,
   modulePathIgnorePatterns: ['assets/'],
   setupFilesAfterEnv: ['./jest.setup.js', 'jest-expect-message'],
-  ...(isBrowser ? {} : { testEnvironment: 'node' }),
+  testEnvironment: 'node',
   testPathIgnorePatterns: [
     'node_modules/',
     'vendor/',
     'tests/fixtures/',
     'tests/helpers/',
     'tests/javascripts/',
-    ...(isBrowser ? [] : ['tests/browser/browser.js']),
   ],
   testMatch: ['**/tests/**/*.js'],
   testLocationInResults: isActions,