Update xtensa-lx requirement from 0.8.0 to 0.9.0

Updates the requirements on [xtensa-lx](https://github.com/esp-rs/xtensa-lx) to permit the latest version.
- [Commits](https://github.com/esp-rs/xtensa-lx/commits)

---
updated-dependencies:
- dependency-name: xtensa-lx
  dependency-type: direct:production
...

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

Cargo.toml

@@ -20,7 +20,7 @@ embedded-hal = { version = "0.2.3", features = ["unproven"] }
 nb = "1.0.0"
 once_cell = { version = "1.4.0", optional = true }
 cortex-m = { version = "0.7.7", optional = true }
-xtensa-lx = { version = "0.8.0", optional = true, features = ["spin"] }
+xtensa-lx = { version = "0.9.0", optional = true, features = ["spin"] }
 spin = { version = "0.9.8", optional = true }
 atomic-polyfill = { version = "1.0.1", optional = true }