You are looking at the HTML representation of the XML format.
HTML is good for debugging, but is unsuitable for application use.
Specify the format parameter to change the output format.
To see the non HTML representation of the XML format, set format=xml.
See the complete documentation, or API help for more information. 
<?xml version="1.0"?>
<api>
  <query-continue>
    <alltransclusions gatcontinue="TOC|1291" />
  </query-continue>
  <query>
    <pages>
      <page pageid="1" ns="0" title="Main Page" />
      <page pageid="1283" ns="0" title="User FAQ" />
      <page pageid="1284" ns="0" title="Developer FAQ" />
      <page pageid="1285" ns="0" title="HOWTOs" />
      <page pageid="1286" ns="0" title="Troubleshooting" />
      <page pageid="1287" ns="0" title="Contributed Code" />
      <page pageid="1288" ns="0" title="Suggested Projects" />
      <page pageid="1289" ns="0" title="Related Projects" />
      <page pageid="1290" ns="0" title="Papers" />
      <page pageid="2059" ns="0" title="GSOC2023ns3-ai" />
    </pages>
  </query>
</api>