I would like a special purpose language to exist precisely for writing crytographic code where you always want the constant time algorithm. In this niche language "We found a 20% speed-up for Blemvich-Smith, oops, it actually isn't constant time on the Arrow Lake micro-code version 18 through 46" wouldn't even get into a nightly let alone be released for use.
It seems that for reasons I don't understand this idea isn't popular and people really like hand rolling assembly.
There's been plenty, like RobustIsoCrypt or FaCT:
https://github.com/PLSysSec/FaCT
They struggle to guarantee constant time for subroutines within a non-constant time application, which is how most people want to use cryptography.