chore: update indexnow key and remove old file

- Update INDEXNOW_KEY value to a new key.
- Remove the old key file (339ecd3e9cf648c29b767f5673329e48.txt).
- Create a new key file (79701a0df5814ed387163513269fd4dd.txt).

This change is necessary due to the rotation of the indexing key. The
old key is no longer valid, and the update ensures continued
functionality with IndexNow services. All references to the old
key have been removed to avoid confusion and ensure that the
new key is correctly used in the worker.

app/workers/submit_to_indexnow_worker.rb

@@ -8,7 +8,7 @@ class SubmitToIndexnowWorker
 
   sidekiq_options retry: 3, queue: :indexnow
 
-  INDEXNOW_KEY = "339ecd3e9cf648c29b767f5673329e48"
+  INDEXNOW_KEY = "79701a0df5814ed387163513269fd4dd"
   INDEXNOW_ENDPOINTS = [
     "https://www.bing.com/indexnow",
     "https://api.indexnow.org/indexnow"

public/339ecd3e9cf648c29b767f5673329e48.txt

@@ -1 +0,0 @@
-339ecd3e9cf648c29b767f5673329e48

public/79701a0df5814ed387163513269fd4dd.txt

@@ -0,0 +1 @@
+79701a0df5814ed387163513269fd4dd