GitHub Updates actions/checkout to Block Common Pwn Request Attack Patterns

GitHub is implementing a security update to its "actions/checkout" action to mitigate a common supply chain attack vector. The update, effective June 18, 2026, will block the execution of malicious code from untrusted forks triggered by the "pull_request_target" workflow event, preventing potential access to sensitive information like GitHub tokens and secrets. This change follows recent supply chain attacks targeting popular software packages.