tests: Update test-helper

Author: taiki-e

Cargo.toml

@@ -39,7 +39,7 @@ build-context = "0.1"
 easy-ext = "1"
 fs-err = "3"
 tempfile = { version = "3", default-features = false }
-test-helper = { features = ["cli", "doc", "git"], git = "https://github.com/taiki-e/test-helper.git", rev = "20a3e10" }
+test-helper = { features = ["cli", "doc", "git"], git = "https://github.com/taiki-e/test-helper.git", rev = "e8333e1" }
 
 [lints]
 workspace = true