e2e: fix Site Editor Styles test (#62111)

* e2e: fix Site Editor Styles test

* Set a px value

Co-authored-by: t-hamano <wildworks@git.wordpress.org>
Co-authored-by: Mamaduka <mamaduka@git.wordpress.org>
Co-authored-by: ellatrix <ellatrix@git.wordpress.org>
Co-authored-by: SantosGuillamot <santosguillamot@git.wordpress.org>
Co-authored-by: youknowriad <youknowriad@git.wordpress.org>

test/e2e/specs/site-editor/styles.spec.js

@@ -45,15 +45,14 @@ test.describe( 'Styles', () => {
 			.getByRole( 'button', { name: 'Social Icons block styles' } )
 			.click();
 
-		// find the second padding control
-		const paddingControl = page
-			.locator( '[aria-label="padding"]' )
-			.nth( 1 );
-
-		// Change the padding value
-		await paddingControl.fill( '2' );
+		// Find the second padding control and change the padding value
+		await page
+			.getByRole( 'button', { name: 'Set custom size' } )
+			.nth( 1 )
+			.click();
+		await page.getByRole( 'spinbutton', { name: 'padding' } ).fill( '35' );
 
 		// Check the padding value
-		await expect( block ).toHaveCSS( 'padding-left', '35.4644px' );
+		await expect( block ).toHaveCSS( 'padding-left', '35px' );
 	} );
 } );