[Infoblox NIOS] Update Grok pattern to handle the new log format

[moxarth-rathod]

Proposed commit message

infoblox_nios: handle additional IP field in syslog format

The existing grok pattern failed to parse logs that include an extra IP 
address field between the priority and hostname. The updated pattern now 
captures this optional IP field and processes it alongside the existing 
host IP field.

Test logs were obtained from the reported issue.

Checklist

• I have reviewed tips for building integrations and this pull request is aligned with them.
• I have verified that all data streams collect metrics or logs.
• I have added an entry to my package's changelog.yml file.
• I have verified that Kibana version constraints are current according to guidelines.
• I have verified that any added dashboard complies with Kibana's Dashboard good practices

How to test this PR locally

• Clone integrations repo.
• Install elastic package locally.
• Start elastic stack using elastic-package.
• Move to integrations/packages/infoblox_nios directory.
• Run the following command to run tests.

elastic-package test

Related issues

• Closes [Infoblox NIOS]: Update initial Grok for updated log format in 9.0.8 #16963

[elasticmachine]

Pinging @elastic/security-service-integrations (Team:Security-Service Integrations)

[elastic-vault-github-plugin-prod]

🚀 Benchmarks report

To see the full report comment with /test benchmark fullreport

[efd6]

Rémy suggests:

infoblox_nios: handle additional IP field in syslog format

The existing grok pattern failed to parse logs that include an extra IP 
address field between the priority and hostname. The updated pattern now 
captures this optional IP field and processes it alongside the existing 
host IP field.

[AUTHOR: Please add test data provenance - where did the new log sample come from?]