Filter out credentials without a host in git_source type (dependabot#12973)

Author: kbukum1

common/lib/dependabot/shared_helpers.rb

@@ -371,6 +371,7 @@ def self.configure_git_to_use_https_with_credentials(credentials, safe_directori
       git_store_content = ""
       deduped_credentials.each do |cred|
         next unless cred["type"] == "git_source"
+        next unless cred["host"]
 
         has_creds = cred["username"] && cred["password"]