Thank You for your support Pushpendra

Thanks a huge lot Pushpendra for your answer! 
I'm sorry to say it did not work, but I learned a lot from it.

I added the class, changed the _onSortColumn as you said, but nothing happened.

I added a console.log before the if just to see if it ever ran, and it is never logged. But the log at the start of the .js file is properly being logged, so it is being imported. 

Is it possible that _onSortColumn isn't what I should target? I've been checking out list_renderer.js and it would seem that it is. But I can barely understand. Luckily, I have permission to read the Javascript Framework at the Odoo docs, three full hours just to study. If you know of any other good source of knowledge on the topic, I would be really grateful too.

Updated .js file:

odoo.define('production_operator_missiongroup.custom_list_renderer', function (require) {    "use strict";

    console.log("Javascript works!")

    var ListRenderer = require('web.ListRenderer');
    var CustomListRenderer = ListRenderer.extend({        
	​	​events: _.extend({}, ListRenderer.prototype.events, {            
'click thead th.o_column_sortable': '_onSortColumn',        
}),

        _onSortColumn: function (ev) {
	​	​	​if (this.$el.hasClass('disable_sort')) {  
              ev.preventDefault();                
	​	​	​return false;            
	​}
            return this._super.apply(this, arguments);        
},    
});
    return CustomListRenderer;});

Updated tree view:

production.work.tree
production.work

	​	​class="disable_sort">
	​	​
	​