[llvm] [Nomination] Add HighTec representatives to the Security Group (PR #124142)

[Yvan Roux via llvm-commits]

yroux wrote:

Even if I don't know Mario personally, I can vouch for him. Mario and HighTec are STMicro trusted partners for more than 10 years for our automotive products, and `git log --pretty=format:"%H %an <%ae>" | grep "hightec"` show ~50 contribution from hightec between 2020 and 2024.

https://github.com/llvm/llvm-project/pull/124142