Fix lint script for app config perf test

[ramya-rao-a]

Perf test packages should not be using the eslint plugin

Fixes the below error

ESLint couldn't find the plugin "@azure/eslint-plugin-azure-sdk".

(The package "@azure/eslint-plugin-azure-sdk" was not found when loaded as a Node module from the directory "/home/vsts/work/1/s/sdk".)

It's likely that the plugin isn't installed correctly. Try reinstalling by running the following:

    npm install @azure/eslint-plugin-azure-sdk@latest --save-dev

The plugin "@azure/eslint-plugin-azure-sdk" was referenced from the config file in "../../../.eslintrc.json".

[ghost]

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