Pass php variables to js without drupal behaviour
You can follow document. 


  Attaching configurable JavaScript
  
  In some cases, you may want to add JavaScript to a page that depends
  on some computed PHP information.
  
  In this case, create a JavaScript file, define and attach a library
  just like before, but also attach JavaScript settings and have that
  JavaScript file read those settings, via drupalSettings (the successor
  to Drupal 7's Drupal.settings). However, to make drupalSettings
  available to our JavaScript file, we have to do the same work as we
  had to do to make jQuery available: we have to declare a dependency on
  it.
  
  So that then becomes:


cuddly-slider:
  version: 1.x
  js:
    js/cuddly-slider.js: {}
  dependencies:
    - core/jquery
    - core/drupalSettings



  and


$build['#attached']['library'][] = 'fluffiness/cuddly-slider';
$build['#attached']['drupalSettings']['fluffiness']['cuddlySlider']['foo'] = 'bar';


Where 'bar' is some calculated value.


  Then cuddly-slider.js will be able to access
  drupalSettings.fluffiness.cuddlySlider.foo (and it will === 'bar').


In your case. You need use hook_preprocess_node() to add array geofield. 

function YOUR_MODULE_preprocess_node($vars) {
  // You nedd process to get $geofield
  $vars['#attached']['drupalSettings']['geoField'] = $geofield
}


and file js/my-googlemaps.js you need code. 

(function($, Drupal, drupalSettings) {
  Drupal.behaviors.yourbehavior = {
    attach: function (context, settings) {
       var geoField = drupalSettings.geoField.
      // You can init map here.
    }
  };
})(jQuery, Drupal, drupalSettings);