Reoptimizes merge bins with only 1 file, even though they have no effect.

[haruband]

Environment

Delta-rs version: 0.17.0

Binding: Rust

Environment:

• Cloud provider:
• OS: MacOS/Linux
• Other:

---

Bug

What happened:
Reoptimizes merge bins with only 1 file, even though they have no effect. This problem only occurs when there are multiple merge bins.

What you expected to happen:
Should not reoptimize merge bins with only 1 file, since they have no effect.

How to reproduce it:

More details: