chore: bump version to 0.9.4

Patch release bundling:
  - fix(solver): IpoptOptions.diverging_iterates_tol default 1e8 → 1e20
    (this PR)
  - feat(ci): Aqua.jl + JET.jl on every PR (#87, #88, merged ahead of
    this one)
  - NT 0.9 compat (already on main via #90)

Non-breaking on all axes — solver tolerance loosens, CI additions are
test-only, NT compat additive.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: jack-champagne

Project.toml

@@ -1,6 +1,6 @@
 name = "DirectTrajOpt"
 uuid = "c823fa1f-8872-4af5-b810-2b9b72bbbf56"
-version = "0.9.3"
+version = "0.9.4"
 authors = ["Aaron Trowbridge <aaron.j.trowbridge@gmail.com> and contributors"]
 
 [deps]