fix: #3614938 Resolve ESLint findings

Summary

Updates comment_notify.js to current Drupal JavaScript formatting, method shorthand, and jQuery event binding standards without changing the checkbox behavior.

Why these changes were needed

Original code	ESLint rule	Why it failed	Resolution
"use strict";	strict	ESLint already treats the file as strict, making the directive unnecessary.	Removed the redundant directive.
attach: function (context)	object-shorthand	Drupal JavaScript standards require object method shorthand.	Changed it to attach(context).
.bind("change", handler)	no-jquery/no-bind	Drupal prohibits the legacy jQuery .bind() event API.	Replaced it with the equivalent .on("change", handler).
Double-quoted JavaScript strings	prettier/prettier	The current Prettier configuration requires single quotes.	Changed the affected strings to single quotes.
Computed show or hide call formatting	prettier/prettier	The expression did not match the configured line wrapping.	Applied the required multiline formatting.
Missing statement terminator	prettier/prettier	The formatted computed method call requires a semicolon.	Added the semicolon.

Behavioral safety

• The Drupal behavior still attaches with the supplied context.
• Both element selectors are unchanged.
• jQuery implements .bind() through .on() for this use case, so the event behavior is equivalent.
• The event callback remains a normal function so this.checked continues to reference the changed checkbox.
• The initial .trigger("change") behavior remains in place.
• No once() behavior was introduced, preserving existing AJAX reattachment behavior.
• Mouse and keyboard activation continue to use the native checkbox change event.

Validation

• Manual browser testing confirmed that selecting Notify me when new comments are posted displays the All comments and Replies to my comment options, and clearing it hides them.
• Complete Comment Notify test directory passed locally: 17 tests and 483 assertions.
• ESLint job passed: https://git.drupalcode.org/project/comment_notify/-/jobs/11364565
• Current MR pipeline completed successfully: https://git.drupalcode.org/project/comment_notify/-/pipelines/912689

Closes #3614938

AI-Generated: Yes (OpenAI Codex inspected CI, implemented and reviewed the focused changes, ran local validation, and assisted with this merge request description. A human reviewed the behavior before merge.)