Obsolete @sentry/webpack-plugin causes source maps being deleted before being uploaded

[julianCast]

Due to a racing condition, the version used in package @sentry/webpack-plugin for gatsby is causing the parameter filesToDeleteAfterUpload not working properly because the maps are being deleted before being uploaded to the server.

That was fixed in "@sentry/webpack-plugin": "2.20.1" More info in this PR.

Current dependency for gatsby obsolete. https://github.com/getsentry/sentry-javascript/blob/9e56c74b2a945ea5c4c33d5fe5c1466e8844e1ad/packages/gatsby/package.json#L52

Depdencency updated for nextJS https://github.com/getsentry/sentry-javascript/blob/9e56c74b2a945ea5c4c33d5fe5c1466e8844e1ad/packages/nextjs/package.json#L81