Fix dimensionality in get_dist function
# What does this PR do ?

Adds back a `squeeze(1)` to the Aligner `get_dist()` function.

This should fix a few cells erroring out in the Aligner inference notebook.

See #7490 for more info.

**Collection**:TTS

**PR Type**:
- [ ] New Feature
- [x] Bugfix
- [ ] Documentation