tools: simplify .eslintrc.js

Remove explicit setting of configuration options in rules when those
options are the defaults.

PR-URL: #45397
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>

.eslintrc.js

@@ -117,8 +117,8 @@ module.exports = {
     // https://eslint.org/docs/rules/
     'accessor-pairs': 'error',
     'array-callback-return': 'error',
-    'arrow-parens': ['error', 'always'],
-    'arrow-spacing': ['error', { before: true, after: true }],
+    'arrow-parens': 'error',
+    'arrow-spacing': 'error',
     'block-scoped-var': 'error',
     'block-spacing': 'error',
     'brace-style': ['error', '1tbs', { allowSingleLine: true }],
@@ -161,9 +161,9 @@ module.exports = {
       ObjectExpression: 'first',
       SwitchCase: 1,
     }],
-    'key-spacing': ['error', { mode: 'strict' }],
+    'key-spacing': 'error',
     'keyword-spacing': 'error',
-    'linebreak-style': ['error', 'unix'],
+    'linebreak-style': 'error',
     'max-len': ['error', {
       code: 120,
       ignorePattern: '^// Flags:',
@@ -177,7 +177,7 @@ module.exports = {
     'no-constant-condition': ['error', { checkLoops: false }],
     'no-constructor-return': 'error',
     'no-duplicate-imports': 'error',
-    'no-else-return': ['error', { allowElseIf: true }],
+    'no-else-return': 'error',
     'no-extra-parens': ['error', 'functions'],
     'no-lonely-if': 'error',
     'no-mixed-requires': 'error',
@@ -284,7 +284,7 @@ module.exports = {
       named: 'never',
       asyncArrow: 'always',
     }],
-    'space-in-parens': ['error', 'never'],
+    'space-in-parens': 'error',
     'space-infix-ops': 'error',
     'space-unary-ops': 'error',
     'spaced-comment': ['error', 'always', {