Bump bech32 from 0.7.3 to 0.9.1 in /rust

Bumps [bech32](https://github.com/rust-bitcoin/rust-bech32) from 0.7.3 to 0.9.1.
- [Release notes](https://github.com/rust-bitcoin/rust-bech32/releases)
- [Commits](rust-bitcoin/rust-bech32@v0.7.3...v0.9.1)

---
updated-dependencies:
- dependency-name: bech32
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

rust/Cargo.lock

@@ -21,7 +21,7 @@ cbor_event = "2.1.3"
 ed25519-bip32 = "0.4.1"
 sha2 = "^0.9"
 digest = "^0.9"
-bech32 = "0.7.2"
+bech32 = "0.9.1"
 hex = "0.4.0"
 cfg-if = "1"
 linked-hash-map = "0.5.3"