docs(js): Document errorHandleroption for nextjs (#14129)

Author: chargome

docs/platforms/javascript/guides/nextjs/configuration/build/index.mdx

@@ -74,6 +74,24 @@ Prints additional debug information about the SDK and uploading source maps when
 
 </SdkOption>
 
+<SdkOption name="errorHandler" type="(error: Error) => void">
+
+A callback function that will be invoked when errors occur during the Sentry build process. This is particularly useful for gracefully handling CI/CD pipeline failures when there are connectivity issues.
+You can optionally re-throw the error to fail the build process.
+
+```javascript
+withSentryConfig(nextConfig, {
+  // ... other options
+  errorHandler: (error) => {
+    console.warn('Sentry build error occurred:', error);
+    // Optionally, you can still fail the build by re-throwing the error
+    // throw error;
+  }
+});
+```
+
+</SdkOption>
+
 ## Source Maps Options
 
 <SdkOption name="sourcemaps.disable" type="boolean">