Use modern @mtkcompile syntax instead of complete()

Updates all system definitions to use the clean modern ModelingToolkit v10 syntax:

**Modernization:**
- Replace `@named sys = let ... complete(ODESystem(eqs, t)) end`
- With `@mtkcompile sys = let ... ODESystem(eqs, t) end`

**Benefits:**
- Uses the official MTK v10 recommended approach
- Cleaner, more readable syntax
- Eliminates deprecated `complete()` function calls
- `@mtkcompile` handles compilation automatically

**Changes Applied:**
- All 88 benchmark systems now use `@mtkcompile` macro
- Removed all `complete()` function calls
- Simplified ODESystem constructor to just `ODESystem(eqs, t)`
- Maintains mathematical correctness and performance

This brings the NonStiffODE benchmarks up to modern ModelingToolkit v10
best practices while resolving the constructor compatibility issues.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <[email protected]>

Author: ChrisRackauckas