fix: update sui wallet changeset (MystenLabs#16005)

## Description 

followup to MystenLabs#15415

## Test Plan 

How did you test the new or updated feature?

---
If your changes are not user-facing and do not break anything, you can
skip the following section. Otherwise, please briefly describe what has
changed under the Release Notes section.

### Type of Change (Check all that apply)

- [ ] protocol change
- [ ] user-visible impact
- [ ] breaking change for a client SDKs
- [ ] breaking change for FNs (FN binary must upgrade)
- [ ] breaking change for validators or node operators (must upgrade
binaries)
- [ ] breaking change for on-chain data layout
- [ ] necessitate either a data wipe or data migration

### Release notes

.changeset/two-olives-enjoy.md

@@ -1,5 +1,5 @@
 ---
-'@mysten/sui.js': major
+'@mysten/sui.js': minor
 ---
 
-Use Bech32 instead of Hex for private key encoding for import and export
+Use Bech32 instead of Hex for private key export, supports both Hex and Bech32 for importing