Update spec/2023-07-draft.md

Co-authored-by: Harry Zhang <[email protected]>

Author: niemela

spec/2023-07-draft.md

@@ -1017,7 +1017,7 @@ A static validator may be provided under the `static_validator` directory, simil
 
 ### Static Validation Test Cases
 
-Each test data group (or `sample, or `secret`) may define a static validation test case.
+Each test data group (or `sample`, or `secret`) may define a static validation test case.
 It is an error to define static validation test cases without providing a static validator.
 A static validation test case is defined in `test_group.yaml` by specifying the key `static_validation_score`.