ci: restricts to RFC9110 methods syntax

Co-authored-by: Henry Andrews <andrews_henry@yahoo.com>

Author: baywet

src/schemas/validation/schema.yaml

@@ -235,6 +235,9 @@ $defs:
         additionalProperties:
           $ref: '#/$defs/operation'
         propertyNames:
+          $comment: RFC9110 restricts methods to "1*tchar" in ABNF
+          pattern: "^[a-zA-Z0-9!#$%&'*+.-]+$"
+ "^" / "_" / "`" / "|" / "~"
           not:
             enum:
               - GET