Rename the effect type effects for OCaml 5.3 keyword compatibility

[bacam]

No description provided.

[github-actions]

Test Results

   12 files  ±0     24 suites  ±0   0s ⏱️ ±0s
  752 tests ±0    752 ✅ ±0  0 💤 ±0  0 ❌ ±0 
2 496 runs  ±0  2 496 ✅ ±0  0 💤 ±0  0 ❌ ±0 

Results for commit 44c9f36. ± Comparison against base commit 49d5bed.

[Alasdair]

Hmm, maybe a good signal to finally remove this. Afaik this is a shim for older code that is relying on the previous effect system with effects added into the AST, rather than the effect inference.

[Alasdair]

Also looking at the OCaml 5.3 features and very happy to see

Re-introduced statistical memory profiling

That was something that was keeping me on 4.X!

[bacam]

I'll merge this for now. The shim also does the job of marking which expressions need to go in the monad, which we'd still need anyway.

[Alasdair]

Yes, I wasn't thinking of removing it entirely just replacing it with a boolean directly