Enable Solidity optimizations

[nlordell]

Enable Solidity optimizations

[fleupold]

Where I saw this being mentioned: https://twitter.com/PhABCD/status/1329847000767094788?s=20

[nlordell]

According to https://docs.soliditylang.org/en/v0.7.5/using-the-compiler.html#input-description, the Yul optimizations are enabled by default since 0.6:

// The new Yul optimizer. Mostly operates on the code of ABI coder v2
// and inline assembly.
// It is activated together with the global optimizer setting
// and can be deactivated here.
// Before Solidity 0.6.0 it had to be activated through this switch.
"yul": false,