Fix potential vulnerable cloned function

[npt-1707]

Hi again,

I identified another potential vulnerability in a clone function singlevar() in src/lua/src/lparser.c sourced from lua/lua. This issue, originally reported in CVE-2022-28805, was resolved in the repository via this commit lua/lua@1f3c6f4.

This PR applies the corresponding patch to fix the vulnerability in this codebase.

Please review at your convenience. Thank you!

[mfisher31]

Hey thanks, but we could just update all of lua to 5.4.7, and it should just work: all that would take is replacing element/src/lua/src with lua-5.4.7/src. Assuming lua didn't change file names or add/remove sources

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