docs: Fix search box [skip tests] (#4226)

closes #4225

Search box has disappeared after upgrading ansys-aphinx-theme from 1.4.2
onwards.

We have downgraded it to 1.4.2 as it is working fine.

Local docs - 


![image](https://github.com/user-attachments/assets/cc67ae07-1c70-4c48-84b7-5b7c51b5c384)

---------

Co-authored-by: pyansys-ci-bot <[email protected]>
Co-authored-by: Revathy Venugopal <[email protected]>

Author: 3 people

doc/changelog.d/4226.documentation.md

@@ -0,0 +1 @@
+Fix search box [skip tests]

doc/source/conf.py

@@ -193,7 +193,6 @@ def _stop_fluent_container(gallery_conf, fname):
         "json_url": f"https://{cname}/versions.json",
         "version_match": get_version_match(__version__),
     },
-    "navbar_end": ["version-switcher", "theme-switcher", "navbar-icon-links"],
     "navigation_depth": -1,
     "collapse_navigation": True,
 }