chore: update lwc to v7.2.6

[nolanlawson]

This is just a regularly-scheduled dependency update.

Thank you as always for continuing to maintain this repo! 🙇

[MrHBS]

Thanks! This should close #1715

[krausest]

Here's a screenshot from an incremental run (left new version, right old version).
Please note that vanillajs was slower on the left. I'm a bit disappointed with that because I'm trying to solve #1721, but as you can see vanillajs perfomed was 0.2 slower (even after reboot and on AC). So I think it's plausible to assume that performance for all updated versions would be better in a full run.