fix: correct forward pass for fast rnns

[MartinuzziFrancesco]

No description provided.

[codecov]

Codecov Report

❌ Patch coverage is 91.66667% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 70.20%. Comparing base (766bb5d) to head (188aadf).
⚠️ Report is 2 commits behind head on main.

Files with missing lines	Patch %	Lines
src/generics.jl	50.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #158      +/-   ##
==========================================
+ Coverage   70.12%   70.20%   +0.07%     
==========================================
  Files          33       33              
  Lines        1590     1594       +4     
==========================================
+ Hits         1115     1119       +4     
  Misses        475      475              

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.