Google Maps JavaScript API has been loaded directly without loading=async

[barryofguilder]

Describe the bug

When I run my app using the <GMap /> component, I get the following warning in the developer console:

"Google Maps JavaScript API has been loaded directly without loading=async. This can result in suboptimal performance. For best-practice loading patterns please see https://goo.gle/js-api-loading"

To Reproduce

Launch an application using the <GMap /> component in it's most basic form. You will see the warning message displayed in the developer console of the browser.

Screenshots

Additional context

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Addon configuration and device details

Addon configuration:

• Addon version: 7.2.1

• Addon config from environment.js (do not post your API key):

'ember-google-maps': {
  key: process.env.GOOGLE_MAPS_API_KEY,
  language: 'en',
  region: 'US',
  protocol: 'https',
  version: '3.55',
},

• Google Maps version: 3.55

Desktop:

• OS: macOS 14.4.1

• Browser: Chrome

• Version: 123.0.6312.124

[sandydoo]

See #193.