Fix the wheel count check for pex building. (#7933)
Fix the wheel count check for pex building. (#7933)

### Problem

#7888 fixed most of the locations that were expecting particular whl counts, but missed one.

### Solution

Fix the last whl count check.

### Result

Confirmed that `build-support/bin/release.sh -p` works.
tdyas/pants,benjyw/pants,tdyas/pants,pantsbuild/pants,wisechengyi/pants,wisechengyi/pants,tdyas/pants,benjyw/pants,pantsbuild/pants,tdyas/pants,wisechengyi/pants,wisechengyi/pants,jsirois/pants,benjyw/pants,tdyas/pants,pantsbuild/pants,pantsbuild/pants,pantsbuild/pants,jsirois/pants,benjyw/pants,benjyw/pants,benjyw/pants,pantsbuild/pants,tdyas/pants,tdyas/pants,tdyas/pants,wisechengyi/pants,jsirois/pants,pantsbuild/pants,tdyas/pants,wisechengyi/pants,wisechengyi/pants,wisechengyi/pants,benjyw/pants,wisechengyi/pants