update next config for better build

this commit change means we no longer get the error:
  "Detected next.config.js, no exported configuration found.
  https://nextjs.org/docs/messages/empty-configuration"

next.config.js

@@ -1,14 +1,11 @@
-// This guard clause allows the app to still build in the event another exception handler will be used,
-// or the sentry project hasn't been set up yet
-if (!process.env.SENTRY_DSN) return
-
 // This file sets a custom webpack configuration to use your Next.js app
 // with Sentry.
 // https://nextjs.org/docs/api-reference/next.config.js/introduction
 // https://docs.sentry.io/platforms/javascript/guides/nextjs/manual-setup/
 const { withSentryConfig } = require('@sentry/nextjs')
+const SENTRY_DSN = process.env.SENTRY_DSN
 
-const nextConfig = {
+let nextConfig = {
   output: 'standalone',
   reactStrictMode: true,
   swcMinify: true,
@@ -18,34 +15,43 @@ const nextConfig = {
     // ref: https://nextjs.org/docs/pages/api-reference/next-config-js/eslint
     ignoreDuringBuilds: true,
   },
-  sentry: {
-    // Use `hidden-source-map` rather than `source-map` as the Webpack `devtool`
-    // for client-side builds. (This will be the default starting in
-    // `@sentry/nextjs` version 8.0.0.) See
-    // https://webpack.js.org/configuration/devtool/ and
-    // https://docs.sentry.io/platforms/javascript/guides/nextjs/manual-setup/#use-hidden-source-map
-    // for more information.
-    hideSourceMaps: true,
-  },
 }
 
-const sentryWebpackPluginOptions = {
-  // Additional config options for the Sentry Webpack plugin. Keep in mind that
-  // the following options are set automatically, and overriding them is not
-  // recommended:
-  //   release, url, configFile, stripPrefix, urlPrefix, include, ignore
-
-  silent: true, // Suppresses all logs
-  project: process.env.SENTRY_PROJECT,
-  org: process.env.SENTRY_ORG,
-  authToken: process.env.SENTRY_AUTH_TOKEN,
-  // For all available options, see:
-  // https://github.com/getsentry/sentry-webpack-plugin#options.
-}
+module.exports = nextConfig
 
 // Make sure adding Sentry options is the last code to run before exporting, to
 // ensure that your source maps include changes from all other Webpack plugins
-module.exports = withSentryConfig(
-  nextConfig,
-  sentryWebpackPluginOptions
-)
+let sentryWebpackPluginOptions = {}
+if (SENTRY_DSN) {
+  nextConfig = {
+    ...nextConfig,
+    sentry: {
+      // Use `hidden-source-map` rather than `source-map` as the Webpack `devtool`
+      // for client-side builds. (This will be the default starting in
+      // `@sentry/nextjs` version 8.0.0.) See
+      // https://webpack.js.org/configuration/devtool/ and
+      // https://docs.sentry.io/platforms/javascript/guides/nextjs/manual-setup/#use-hidden-source-map
+      // for more information.
+      hideSourceMaps: true,
+    },
+  }
+
+  sentryWebpackPluginOptions = {
+    // Additional config options for the Sentry Webpack plugin. Keep in mind that
+    // the following options are set automatically, and overriding them is not
+    // recommended:
+    //   release, url, configFile, stripPrefix, urlPrefix, include, ignore
+
+    silent: true, // Suppresses all logs
+    project: process.env.SENTRY_PROJECT,
+    org: process.env.SENTRY_ORG,
+    authToken: process.env.SENTRY_AUTH_TOKEN,
+    // For all available options, see:
+    // https://github.com/getsentry/sentry-webpack-plugin#options
+  }
+
+  module.exports = withSentryConfig(
+    nextConfig,
+    sentryWebpackPluginOptions
+  )
+}