Update strum requirement from 0.24 to 0.26 in /xtask

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

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

xtask/Cargo.toml

@@ -32,7 +32,7 @@ duct = "0.13.6"
 serde = { features = ["derive"], version = "1" }
 serde_json = "1"
 smart-default = "0.6"
-strum = { features = ["derive"], version = "0.24" }
+strum = { features = ["derive"], version = "0.26" }
 tracing = "0.1"
 tracing-subscriber = "0.3"