sqf: optimize _this call

[BrettMayson]

• Optimizes _this call to just call
• Off by default lint

[codecov]

Codecov Report

Attention: Patch coverage is 69.30693% with 31 lines in your changes missing coverage. Please review.

Project coverage is 68.2%. Comparing base (4d93c00) to head (e33cdc5).
Report is 3 commits behind head on main.

Files with missing lines	Patch %	Lines
libs/sqf/src/analyze/lints/s22_this_call.rs	74.1%	24 Missing ⚠️
libs/sqf/src/compiler/optimizer/mod.rs	12.5%	7 Missing ⚠️

Additional details and impacted files

Files with missing lines	Coverage Δ
libs/sqf/src/compiler/optimizer/mod.rs	78.8% <12.5%> (-1.9%)	⬇️
libs/sqf/src/analyze/lints/s22_this_call.rs	74.1% <74.1%> (ø)