fix: remove unsupported name field from DerivedField schema

The DerivedField type in _common.yaml declares a 'name' property and
marks it as required, but OpenSearch does not recognize this field in
mapping definitions. When a client serializes a DerivedField with 'name'
set, the server rejects the request with a mapper_parsing_exception:

  [mapper_parsing_exception] Failed to parse mapping: unknown parameter [name]

Remove the 'name' property from DerivedField.properties and from the
required list so the schema matches the actual server behavior.

Signed-off-by: RadhaKrishnan Rajendran <gingeekrishna@gmail.com>
Signed-off-by: Radhakrishnan Pachyappan <radhakrishnan.p@op.tech>

Author: gingeekrishna

spec/schemas/_common.yaml

@@ -576,8 +576,6 @@ components:
     DerivedField:
       type: object
       properties:
-        name:
-          type: string
         type:
           type: string
         script:
@@ -591,7 +589,6 @@ components:
         format:
           type: string
       required:
-        - name
         - script
         - type
     Sort: