Fix broadcasting bug in vectorization of RandomVariables

[ricardoV94]

Description

This showed up in #691 and was introduced/not properly handled by #664

We need to explicitly broadcast the new parameters to define the new size!

Checklist

• Checked that the pre-commit linting/style checks pass
• Included tests that prove the fix is effective or that the new feature works
• Added necessary documentation (docstrings and/or example notebooks)
• If you are a pro: each commit corresponds to a relevant logical change

Type of change

• New feature / enhancement
• Bug fix
• Documentation
• Maintenance
• Other (please specify):

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 80.81%. Comparing base (044910b) to head (a745bc1).
Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #738   +/-   ##
=======================================
  Coverage   80.81%   80.81%           
=======================================
  Files         162      162           
  Lines       46805    46813    +8     
  Branches    11451    11453    +2     
=======================================
+ Hits        37825    37834    +9     
  Misses       6730     6730           
+ Partials     2250     2249    -1     

Files	Coverage Δ
pytensor/tensor/random/op.py	96.87% <100.00%> (+0.60%)	⬆️
pytensor/tensor/random/utils.py	100.00% <100.00%> (ø)

... and 1 file with indirect coverage changes