fix: enable shell mode for spawn to resolve Windows EINVAL issue

[tylerablackham]

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This change addresses issue: #2111 / #2114

[jaylinski]

Note: CI lint fail has nothing to do with this change. We have to fix this separately.

[biplavbarua]

Verified locally on macOS. The grunt parser task runs successfully. The DeprecationWarning regarding shell: true is observed but acceptable here since the arguments are hardcoded file paths, minimizing injection risk. This change should resolve the Windows spawn issues as intended. LGTM.

[jaylinski]

Thank you!