linter: `oxlint` does the follow the complete `extends` chain.

[ValentinGurkov]

What version of Oxlint are you using?

0.16.8

What command did you run?

oxlint --fix --deny-warnings

What does your .oxlintrc.json config file look like?

// .oxlintrc.json
{
    "$schema": "./node_modules/oxlint/configuration_schema.json",
    "extends": ["./.oxlintrc.extended.json"]
}

// .oxlintrc.extended.json
{
    "$schema": "./node_modules/oxlint/configuration_schema.json",
    "extends": ["./.oxlintrc.base.json"]
}

// .oxlintrc.base.json
{
    "$schema": "./node_modules/oxlint/configuration_schema.json",
    "plugins": ["typescript", "unicorn", "perf", "oxc", "import", "promise", "node", "vitest", "jest"],
    "categories": {
        "correctness": "off",
        "suspicious": "off",
        "pedantic": "off",
        "perf": "off",
        "style": "off",
        "restriction": "off",
        "nursery": "off"
    },
    "ignorePatterns": ["**/node_modules", "pnpm-lock.yaml"],
    "rules": {
        "no-unused-vars": "off"
    }
}

What happened?

Hello,

I've found that oxlint does not go through the full chain of extends, instead it stops after the first.
I don't know if that's by design, but such a chain of extends can be common, mostly in monorepo scenarios.

I have created a minimal repository where this can be observed https://github.com/ValentinGurkov/oxlint-extends-chain

The chain of extends is as follows: .oxlintrc.json -> .oxlintrc.extended.json -> .oxlintrc.base.json and .oxlintrc.base.json disables no-unused-vars which seems to be enabled by default. The configuration from .oxlintrc.base.json does not get applied and warning is reported for no-unsed-vars on the file in the repository,

If I extend directly .oxlintrc.base.json and skip .oxlintrc.extended.json, then the rule is applied.