refactor(nginx): secret region location

packages/nginx/etc/nginx/templates/location.d/90-region-secret.conf.template

@@ -0,0 +1,8 @@
+# Secret region
+# Deny secret locations
+
+location ^~ /$storeRegionSecret/ {
+  return 444; # close connection without sending a response header.
+}
+
+# Note: The ^~ modifier in Nginx is used to match location blocks against the longest non-regular expression prefix of a requested URI. This means that if a location block with the ^~ modifier is matched, no other location blocks will be considered, even if they have regular expression matches. This prevents the regular expression location blocks from taking precedence over the longer prefix matches.