JSON-schema fixes to allow more flexible OAS3.0/3.1 integration

[fmigneault]

Fixes highlighted in opengeospatial/ogcapi-processes#561

Avoids some OAS 3.0/3.1 vs JSON-schema subtleties, notably:

• type arrays (OAS3.0 doesn't like them)
  ➡️ oneOf of these type one by one
• exclusiveMinimum as bool (OAS3.0) vs numeric (all others)
  ➡️ just remove it, use minimum: 0 as "close enough"
• missing type: 'null' support (OAS3.0 using nullable: true)
  ➡️ "hack" enum: [null], nullable: true (OAS3.1 and pure JSON-schema should ignore nullable)
• remove InlineJavascriptLibraries.expressionLib marked as required
  ➡️ it is not required (https://www.commonwl.org/v1.2/CommandLineTool.html#InlineJavascriptRequirement)
  it was not raising before because the indent of required was wrong and ignored
• remove additional properties (copy-paste error?) from ScatterMethod string
  (properties that were listed are relevant for ToolTimeLimit requirement/hint, and are defined)

Sample integration with Swagger in the context of OGC API processes that needs OAS 3.0.

openapi: 3.0.0
info:
   version: '2.0'
   title: "OGC API - Processes"
paths:
  "/processes":
    post:
      requestBody:
        description: |-
          An OGC Application Package used to deploy a new process.
        required: true
        content:
          #application/ogcapppkg+json:
          #  schema:
          #    $ref: "https://raw.githubusercontent.com/opengeospatial/ogcapi-processes/refs/heads/master/openapi/schemas/processes-dru/ogcapppkg.yaml"
          application/cwl:
            schema:
              $ref: "https://raw.githubusercontent.com/fmigneault/cwl-v1.2/refs/heads/fix-json-schema/json-schema/cwl.yaml"
          application/cwl+json:
            schema:
              $ref: "https://raw.githubusercontent.com/fmigneault/cwl-v1.2/refs/heads/fix-json-schema/json-schema/cwl.yaml"
          application/cwl+yaml:
            schema:
              $ref: "https://raw.githubusercontent.com/fmigneault/cwl-v1.2/refs/heads/fix-json-schema/json-schema/cwl.yaml"
      responses:
        "204":
          description: "no body"

[fmigneault]

@mr-c FYI
Corresponding definitions seems to be functional on OGC side.

[mr-c]

Thank you @fmigneault !