### Motivation (apache#4991)

Fixes apache#4990

Master Issue: apache#4990

### Motivation
[pjax-api](https://github.com/falsandtru/pjax-api) conflicts with [scrollSpy](https://github.com/facebook/docusaurus/blob/e486d3d1b0e0a397f242368357fbedbe767104c7/packages/docusaurus-1.x/lib/static/js/scrollSpy.js). Cause that cache headingsCache used by variable findHeadings to not be update correctly.

Modifications
* Delete file pjax-api.min.js

### Verifying this change

Run ok locally

site2/website/core/Footer.js

@@ -165,22 +165,6 @@ class Footer extends React.Component {
         <span>
         <script dangerouslySetInnerHTML={{__html: communityMenuJs }} />
         </span>
-        <span>
-        <script src={this.props.config.baseUrl + 'js/pjax-api.min.js'} />
-        <script dangerouslySetInnerHTML={{__html: `window.navfoo = new Pjax({
-            areas: [
-              // try to use the first query.
-              '.mainContainer, .docsNavContainer .toc .navWrapper, .onPageNav',
-              // fallback
-              'body'
-            ],
-            link: '.docsNavContainer:not(.docsSliderActive) a',
-            update: {
-              script: false,
-            }
-          });
-        `}}></script>
-        </span>
       </footer>
     );
   }