PHP8.2 + minishlink/web-push v7 compatibility

What's Changed

• Fixed PHP Deprecations (ArrayAccess interface) by @svenpet90 in #36
• Updated minishlink/web-push to 7.0 by @easis in #37

New Contributors

• @svenpet90 made their first contribution in #36
• @easis made their first contribution in #37

Full Changelog: 0.8...0.9