🌐 Update pt-BR translation of search.json (#21100)

Following commit #21055, the following updates were made:

Added translations for terms related to authors, posts, search, and
tags.

ghost/i18n/locales/pt-BR/search.json

@@ -1,9 +1,9 @@
 {
-    "Authors": "",
-    "Cancel": "",
-    "No matches found": "",
-    "Posts": "",
-    "Search posts, tags and authors": "",
-    "Show more results": "",
-    "Tags": ""
+    "Authors": "Autores",
+    "Cancel": "Cancelar",
+    "No matches found": "Nenhuma correspondência encontrada",
+    "Posts": "Publicações",
+    "Search posts, tags and authors": "Buscar publicações, tags e autores",
+    "Show more results": "Mostrar mais resultados",
+    "Tags": "Tags"
 }