fix(techdocs): to update title and subtitle when location changes

Signed-off-by: Camila Belo <camilaibs@gmail.com>

.changeset/techdocs-jeans-wait.md

@@ -0,0 +1,5 @@
+---
+'@backstage/plugin-techdocs': patch
+---
+
+Always update the title and sub-title when the location changes on a `TechDocs` reader page.

plugins/techdocs/src/reader/components/TechDocsReaderPageHeader/TechDocsReaderPageHeader.tsx

@@ -77,16 +77,13 @@ export const TechDocsReaderPageHeader = (
 
   useEffect(() => {
     if (!metadata) return;
-    setTitle(prevTitle => {
-      const { site_name } = metadata;
-      return prevTitle || site_name;
-    });
-    setSubtitle(prevSubtitle => {
+    setTitle(metadata.site_name);
+    setSubtitle(() => {
       let { site_description } = metadata;
       if (!site_description || site_description === 'None') {
         site_description = 'Home';
       }
-      return prevSubtitle || site_description;
+      return site_description;
     });
   }, [metadata, setTitle, setSubtitle]);