Add Linea [don't merge] [duplicates repo]

[arwer13]

This PR duplicates code from https://github.com/Consensys/linea-contracts-fix/commit/0949c4096664e613f73ed3ce51c32f97fc56cdef to add more redundancy in keeping track of the code deployed on-chain.

It is not planned for merging (at least yet) due to the merge conflicts.

[arwer13]

Decided instead to fork the repos to keep the commit hashes mentioned in the audits:

• https://github.com/lidofinance/linea-contracts-fix
• https://github.com/lidofinance/linea-contracts