fix: function shadows for higher-order Enzyme

[gdalle]

Presumably fixes #942

Needs tests

[codecov]

Codecov Report

❌ Patch coverage is 90.00000% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 98.19%. Comparing base (325f2b8) to head (854834d).
⚠️ Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
...ace/ext/DifferentiationInterfaceEnzymeExt/utils.jl	84.61%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #943      +/-   ##
==========================================
- Coverage   98.21%   98.19%   -0.03%     
==========================================
  Files         133      133              
  Lines        7976     7981       +5     
==========================================
+ Hits         7834     7837       +3     
- Misses        142      144       +2     

Flag	Coverage Δ
DI	98.96% <90.00%> (-0.04%)	⬇️
DIT	96.19% <ø> (ø)

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[timholy]

For tests, the one-liner in #942 (comment) was able to trigger #942. I just wasn't able to verify that the fixed worked due to other errors thrown after the first one stopped happening.

[gdalle]

Let's merge this, the changes are sound even though Enzyme still errors which prevents proper testing. I'll figure out a pure-Enzyme MWE when I have time