Leave only chromium for perf testing

test/performance/playwright.config.ts

@@ -60,29 +60,6 @@ const config = defineConfig( {
 			use: { ...devices[ 'Desktop Chrome' ] },
 			grepInvert: /-chromium/,
 		},
-		{
-			name: 'webkit',
-			use: {
-				...devices[ 'Desktop Safari' ],
-				/**
-				 * Headless webkit won't receive dataTransfer with custom types in the
-				 * drop event on Linux. The solution is to use `xvfb-run` to run the tests.
-				 * ```sh
-				 * xvfb-run npm run test:e2e:playwright
-				 * ```
-				 * See `.github/workflows/end2end-test-playwright.yml` for advanced usages.
-				 */
-				headless: os.type() !== 'Linux',
-			},
-			grep: /@webkit/,
-			grepInvert: /-webkit/,
-		},
-		{
-			name: 'firefox',
-			use: { ...devices[ 'Desktop Firefox' ] },
-			grep: /@firefox/,
-			grepInvert: /-firefox/,
-		},
 	],
 } );