Update hashbrown requirement from 0.11 to 0.13 in /lightning-invoice

Updates the requirements on [hashbrown](https://github.com/rust-lang/hashbrown) to permit the latest version.
- [Release notes](https://github.com/rust-lang/hashbrown/releases)
- [Changelog](https://github.com/rust-lang/hashbrown/blob/master/CHANGELOG.md)
- [Commits](rust-lang/hashbrown@v0.11.0...v0.13.1)

---
updated-dependencies:
- dependency-name: hashbrown
  dependency-type: direct:production
...

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

Author: dependabot[bot]

lightning-invoice/Cargo.toml

@@ -25,7 +25,7 @@ lightning = { version = "0.0.113", path = "../lightning", default-features = fal
 secp256k1 = { version = "0.24.0", default-features = false, features = ["recovery", "alloc"] }
 num-traits = { version = "0.2.8", default-features = false }
 bitcoin_hashes = { version = "0.11", default-features = false }
-hashbrown = { version = "0.8", optional = true }
+hashbrown = { version = "0.13", optional = true }
 serde = { version = "1.0.118", optional = true }
 
 [dev-dependencies]