Use intermediate environment variable in actions

[ahsan-z-khan]

Description of changes:
These changes should eliminate script injection vulnerabilities by:

• Using environment variables to pass GitHub context safely and Properly quoting all variable references
• Validating all user inputs with regex patterns
• Using jq's --arg parameter for safe JSON construction

Approach from here - https://docs.github.com/en/actions/reference/security/secure-use#use-an-intermediate-environment-variable

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