Consolidate and fix GitHub Actions workflows

[ruhdevops]

This PR consolidates several redundant PowerShell workflows into a single, cross-platform CI workflow. It also updates existing actions and adds dynamic titles to notices for better visibility on GitHub Mobile.

Key changes:

• Consolidated PowerShell CI into a single, cross-platform workflow (.github/workflows/powershell-ci.yml) using a matrix of [ubuntu-latest, windows-latest, macos-latest].
• Removed redundant workflow files: ci.yml and powershell.yml.
• Cleaned up codeql.yml to remove duplicate PowerShell scanning.
• Upgraded actions/setup-node@v3 to v4 in download-cert.yml.
• Added dynamic content (run number) to all ::notice and ::error titles to distinguish between runs and improve mobile visibility.
• Verified all YAML syntax using ruby -ryaml.

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PR created automatically by Jules for task 11519209158851330586 started by @Ruh-Al-Tarikh

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