Selector: Eliminate selector.js depenencies from various modules

There are two main reasons for why some of those dependencies are no longer
needed:
1. `jQuery.contains` which is now a part of `core`.
2. `jQuery.find.attr` no longer exists, native `getAttribute` is used instead.

Closes gh-5383
Ref gh-5379

Author: mgol

Diff for: src/attributes/attr.js

@@ -4,8 +4,6 @@ import { nodeName } from "../core/nodeName.js";
 import { rnothtmlwhite } from "../var/rnothtmlwhite.js";
 import { isIE } from "../var/isIE.js";
 
-import "../selector.js";
-
 jQuery.fn.extend( {
 	attr: function( name, value ) {
 		return access( this, jQuery.attr, name, value, arguments.length > 1 );

Diff for: src/attributes/prop.js

@@ -2,8 +2,6 @@ import { jQuery } from "../core.js";
 import { access } from "../core/access.js";
 import { isIE } from "../var/isIE.js";
 
-import "../selector.js";
-
 var rfocusable = /^(?:input|select|textarea|button)$/i,
 	rclickable = /^(?:a|area)$/i;
 

Diff for: src/css.js

@@ -17,7 +17,6 @@ import { support } from "./css/support.js";
 
 import "./core/init.js";
 import "./core/ready.js";
-import "./selector.js"; // contains
 
 var
 

Diff for: src/manipulation.js

@@ -15,7 +15,6 @@ import { nodeName } from "./core/nodeName.js";
 
 import "./core/init.js";
 import "./traversing.js";
-import "./selector.js";
 import "./event.js";
 
 var

Diff for: src/offset.js

@@ -5,7 +5,6 @@ import { isWindow } from "./var/isWindow.js";
 
 import "./core/init.js";
 import "./css.js";
-import "./selector.js"; // contains
 
 jQuery.offset = {
 	setOffset: function( elem, options, i ) {