chore: add final LF in package.json

...because `yarn version` ignores our editorconfig

.editorconfig

@@ -8,6 +8,3 @@ charset = utf-8
 trim_trailing_whitespace = true
 insert_final_newline = true
 quote_type = single
-
-[package.json]
-insert_final_newline = false

gulpfile.js

@@ -112,7 +112,7 @@ async function bump() {
   } else {
     pkg.beta = (+pkg.beta || 0) + 1;
   }
-  await fs.writeFile('package.json', JSON.stringify(pkg, null, 2), 'utf8');
+  await fs.writeFile('package.json', JSON.stringify(pkg, null, 2) + '\n', 'utf8');
   if (process.argv.includes('--commit')) {
     const version = `v${getVersion()}`;
     spawn.sync('git', ['commit', '-am', version]);

package.json

@@ -116,4 +116,4 @@
     "testEnvironment": "./test/mock/env.js"
   },
   "beta": 10
-}
+}