Deprecate top-level webpack options and move them into a config.webpack namespace

[chargome]

Since Next.js apps can be run in both webpack and turbopack we want to avoid confusion with our withSentryConfig build-time options. To ensure this we need to move all options that do not affect turbopack to it's own namespace.

[linear]

JS-1111

[logaretm]

I traced the options and ended up with these on my list, I might have missed a few but I will start with those.

Option	Webpack only?
autoInstrumentServerFunctions	Only checked in webpack.ts, adds webpack module rules to wrap pages and API routes
autoInstrumentMiddleware	Only checked in webpack.ts, adds webpack module rules to wrap middleware files
autoInstrumentAppDirectory	Only checked in webpack.ts, adds webpack module rules to wrap server components and route handlers
excludeServerRoutes	Only passed to webpack loaders via staticWrappingLoaderOptions, unused in turbopack
widenClientFileUpload	Only affects webpack plugin's source map asset patterns in getBuildPluginOptions for webpack builds
unstable_sentryWebpackPluginOptions	Direct overrides for @sentry/webpack-plugin, merged in getBuildPluginOptions for both webpack and after-production-compile
disableSentryWebpackConfig	Guards the entire webpack configuration injection at line 366 of withSentryConfig.ts
disableLogger	Only checked in webpack.ts line 434, uses webpack's DefinePlugin to set __SENTRY_DEBUG__
automaticVercelMonitors	Only checked in webpack.ts line 242, passes vercelCronsConfig to webpack loaders
reactComponentAnnotation	Disabled for after-production-compile builds in getBuildPluginOptions.ts line 272 (turbopack uses after-production-compile hook)