fix: remove HEADING overrides that break table column labels

COM_MODULES_HEADING_MODULE and COM_PLUGINS_HEADING_NAME are table
column headers in list views, not branding text. Overriding them
breaks sortable table headers and filter labels in Contacts and
other components that share the HEADING pattern.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/administrator/language/overrides/en-GB.override.ini

@@ -50,8 +50,6 @@ JERROR_LAYOUT_ERROR_HAS_OCCURRED="ERROR OCCURRED"
 ; ===== Admin-specific branding =====
 COM_ADMIN_VIEW_HOME_TITLE="{{BRAND_NAME}} Control Panel"
 JLIB_APPLICATION_ERROR_SAVE_FAILED="{{BRAND_NAME}} Error: Save failed"
-COM_MODULES_HEADING_MODULE="{{BRAND_NAME}} Module"
-COM_PLUGINS_HEADING_NAME="{{BRAND_NAME}} Plugin"
 
 ; ===== Extensions =====
 COM_INSTALLER_TYPE_TYPE_JOOMLA="{{BRAND_NAME}}"

src/administrator/language/overrides/en-US.override.ini

@@ -50,8 +50,6 @@ JERROR_LAYOUT_ERROR_HAS_OCCURRED="ERROR OCCURRED"
 ; ===== Admin-specific branding =====
 COM_ADMIN_VIEW_HOME_TITLE="{{BRAND_NAME}} Control Panel"
 JLIB_APPLICATION_ERROR_SAVE_FAILED="{{BRAND_NAME}} Error: Save failed"
-COM_MODULES_HEADING_MODULE="{{BRAND_NAME}} Module"
-COM_PLUGINS_HEADING_NAME="{{BRAND_NAME}} Plugin"
 
 ; ===== Extensions =====
 COM_INSTALLER_TYPE_TYPE_JOOMLA="{{BRAND_NAME}}"