chore: Bump ext test lib to 1.3.0

[ItoroD]

Description

I’ve been dealing with recurring transient dependency issues that required local version update just to test FFI changes. It likely stems from a mismatch between the current Gradle and Kotlin versions. Rather than spending more time debugging the specific conflict, I’ve bumped the versions.

Notes to the reviewers

Documentation

• bdk_wallet
• bitcoin
• uniffi
• Other:

Checklists

All Submissions:

• I've signed all my commits
• I followed the contribution guidelines
• I ran cargo fmt and cargo clippy before committing
• I've added a changelog in the next release tracking issue (see example)
• I've linked the relevant upstream docs or specs above

[reez]

utACK babd466

(Not an android dev)

[thunderbiscuit]

ACK babd466.