Fix the upgrade GitHub action

syslog-ng/syslog-ng#4755 added a `name` keyword
that cause confusion for our simle script.

Ensure we are processing an actual `{"name": "string"}` and not
somthing like `{"name": {...}}` to find keywords.

Author: smortex

generate

@@ -16,7 +16,7 @@ db = JSON.parse(File.read(ARGV[0]))
 def find_keywords(hash)
   keywords = []
   hash.each do |key, value|
-    if key == 'name' && value && !value.start_with?('<')
+    if key == 'name' && value && value.is_a?(String) && !value.start_with?('<')
       keywords << value
       keywords << value.gsub('-', '_')
     elsif value.is_a?(Hash)