[cr134] side_search_param/side_image_search_param removed

This field is gone however it was not being used in brave anyway, and it
was just being referred for instantiation/copies.

Chromium change:
https://chromium.googlesource.com/chromium/src/+/e7adca16d31ff65896b85708e5541aa20760b1c9

commit e7adca16d31ff65896b85708e5541aa20760b1c9
Author: Justin Donnelly <[email protected]>
Date:   Tue Jan 21 14:50:02 2025 -0800

    [search_engines] Remove side_search_param and side_image_search_param.

    These values are unused after the code cleanup tracked in the bug. After this lands, I will make an upstream change remove the values from prepopulated_engines.json.

    Bug: 357910230

components/search_engines/brave_prepopulated_engines.cc

@@ -36,8 +36,6 @@ PrepopulatedEngine MakeBravePrepopulatedEngine(const char16_t* const name,
           /*search_url_post_params=*/nullptr,
           /*suggest_url_post_params=*/nullptr,
           /*image_url_post_params=*/nullptr,
-          /*side_search_param=*/nullptr,
-          /*side_image_search_param=*/nullptr,
           /*image_translate_source_language_param_key=*/nullptr,
           /*image_translate_target_language_param_key=*/nullptr,
           /*image_search_branding_label=*/nullptr,
@@ -89,8 +87,6 @@ PrepopulatedEngine ModifyEngineParams(const PrepopulatedEngine& engine,
           engine.search_url_post_params,
           engine.suggest_url_post_params,
           engine.image_url_post_params,
-          engine.side_search_param,
-          engine.side_image_search_param,
           engine.image_translate_source_language_param_key,
           engine.image_translate_target_language_param_key,
           engine.image_search_branding_label,