Update thiserror requirement from 1.0 to 2.0 in /task-maker-exec

Updates the requirements on [thiserror](https://github.com/dtolnay/thiserror) to permit the latest version.
- [Release notes](https://github.com/dtolnay/thiserror/releases)
- [Commits](dtolnay/thiserror@1.0.0...2.0.3)

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

Signed-off-by: dependabot[bot] <[email protected]>

task-maker-exec/Cargo.toml

@@ -11,7 +11,7 @@ task-maker-cache = { path = "../task-maker-cache" }
 
 # Generic error utilities
 anyhow = { version = "1.0", features = ["backtrace"] }
-thiserror = "1.0"
+thiserror = "2.0"
 # Serialization/Deserialization
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"