chore: remove webpack from dependency

[Bobgy]

Description of your changes:
Part of #4682

A problem I saw:
renovate updated webpack, but not react-scripts. Then frontend fails to build because each version of react-scripts works with a specific chosen version of webpack.

Change in this PR:
Remove webpack from dependency, and include it via react-scripts's transitive dependency.
In this way, webpack's version will be decided by react-scripts, so they won't be out-of-sync during renovate auto-upgrade.

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[Bobgy]

/assign @zijianjoy
Can you help me review?

[zijianjoy]

/lgtm
/approve

Thank you Yuan for fixing the dependency versioning issue! Normally I would prefer to see the webpack version being set explicitly (since the version of module bundling tool might affect the build result), but understanding that this is for resolving the renovate dashboard PR issue.

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[google-oss-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: Bobgy, zijianjoy

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[Bobgy]

@zijianjoy For clarification, that was not the only reason. react-scripts is the core package in https://github.com/facebook/create-react-app and create-react-app is a zero-config bundling tool which uses webpack. So we can take create-react-app as the bundling tool interface, while webpack is an implementation detail. When react-scripts choose a webpack version, we should not use a different version.

The reason we included webpack directly before, was because we migrated to create-react-app and the migration didn't update all dependencies cleanly. Ideally, we should remove webpack as direct dependency when we onboarded create-react-app

[zijianjoy]

@zijianjoy For clarification, that was not the only reason. react-scripts is the core package in https://github.com/facebook/create-react-app and create-react-app is a zero-config bundling tool which uses webpack. So we can take create-react-app as the bundling tool interface, while webpack is an implementation detail. When react-scripts choose a webpack version, we should not use a different version.

The reason we included webpack directly before, was because we migrated to create-react-app and the migration didn't update all dependencies cleanly. Ideally, we should remove webpack as direct dependency when we onboarded create-react-app

That makes sense, thank you for the clarification!