Boost carousel posts not center aligned in multicolumn

**Describe the bug**
dev.phanpy.social
When using multi-column (4 columns in this case), scrolling through the boost carousel doesn't center align the posts, eventually leading to them being cut off on the right side.

**To Reproduce**
Steps to reproduce the behavior:
1. Enable multi-column on dev.phanpy.social
2. Add 4 columns
3. Scroll down to boost carousel
4. Click to scroll sideways through boost carousel a few times until posts start to get cut off on the right side.

**Expected behavior**
Posts should align center in the boosts carousel

**Screenshots**

**Desktop (please complete the following information):**
- OS: Linux
- Browser: Librewolf (Firefox)