chore: add security scanning workflows

[haribabug]

Security Scanning Workflows Enablement

This PR adds standardized security scanning workflows and configurations from ROCm/rocm-repo-template.

Security Controls

• PR Security Scan
• Weekly Security Scan
• Dependabot
• CodeQL, Bandit, Gitleaks, Trivy, and Zizmor

Files added / updated

• .github/workflows/pr-security-scan.yml — scans every pull request
• .github/workflows/weekly-security-scan.yml — scheduled weekly scan
• .github/dependabot.yml — automated dependency updates
• .github/scan_tools_configs/bandit.yml — Python static analysis config
• .github/scan_tools_configs/gitleaks.toml — secret detection config
• .github/scan_tools_configs/trivy.yml — container/dependency vulnerability config
• .github/scan_tools_configs/zizmor.yml — GitHub Actions security config

Why

This change aligns this repository with the ROCm GitHub Organization Security Baseline and enables consistent security controls across ROCm repositories.

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For more details, refer ROCm GitHub Org Security Controls Baseline Architecture

Support/Questions: Teams Channel ROCm Security Discussions

[github-advanced-security]

You are seeing this message because GitHub Code Scanning has recently been set up for this repository, or this pull request contains the workflow file for the Code Scanning tool.

What Enabling Code Scanning Means:

• The 'Security' tab will display more code scanning analysis results (e.g., for the default branch).
• Depending on your configuration and choice of analysis tool, future pull requests will be annotated with code scanning analysis results.
• You will be able to see the analysis results for the pull request's branch on this overview once the scans have completed and the checks have passed.

For more information about GitHub Code Scanning, check out the documentation.