chore: update snyk policy to ignore one of non-applicable ELECTRON vuln and extend the expity of aggrid-community package

[himanshusinghs]

Description

This PR adds an ignore for SNYK-JS-ELECTRON-7443355 despite having a fix for this in main (#6041) because:

1. Snyk does not yet recognise that Electron update 29.4.5 fixes the mentioned CVE
2. The vulnerability does not apply to us

Have also extended the expiry of vuln related to aggridcommunity.

Checklist

• New tests and/or benchmarks are included
• Documentation is changed or added
• I have signed the MongoDB Contributor License Agreement (https://www.mongodb.com/legal/contributor-agreement)

Motivation and Context

• Bugfix
• New feature
• Dependency update
• Misc

Open Questions

Dependents

Types of changes

• Backport Needed
• Patch (non-breaking change which fixes an issue)
• Minor (non-breaking change which adds functionality)
• Major (fix or feature that would cause existing functionality to change)