rest-api-spec: remove required: false for query parameters

[pquentin]

The vast majority of query parameters are not required, but most of them don't specify it. Removing "required": false entirely will help generate the rest-api-spec from the Elasticsearch specification by just not including it when not needed.

This was done using this Python script:

import json
import os

for path in os.listdir("api"):
    if path == "_common.json":
        continue
    api_name = path.removesuffix(".json")
    print(api_name)
    with open(f"api/{path}") as f:
        d = json.load(f)

    for name, data in d[api_name].get("params", {}).items():
        if data.get("required") == False:
            data.pop("required")

    with open(f"api/{path}", "w") as f:
        d = json.dump(d, f, indent=2)
        print("", file=f)  # end with an empty line

[elasticsearchmachine]

Pinging @elastic/es-core-infra (Team:Core/Infra)