Update thiserror requirement from 1 to 2 in /spiffe

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...2.0.0)

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

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

spiffe/Cargo.toml

@@ -16,7 +16,7 @@ keywords = ["SPIFFE", "X509", "JWT"]
 
 [dependencies]
 # spiffe-types dependencies:
-thiserror = "1"
+thiserror = "2"
 url = "2"
 asn1 = { package = "simple_asn1", version = "0.6" }
 x509-parser = "0.16"