AWS Lambda Integration does not support all AWS regions

### Environment

SaaS ([https://sentry.io/]())

### Steps to Reproduce

Activate AWS Lambda Integration in account
Install Sentry AWS CloudFormation Stack (creating a sentry IAM role)
Follow setup tutorial and click on "I installed the stack"
In the next configuration window, attempt to select the AWS region
Attempt to select my **region eu-central-2 (not present!)**

### Expected Result

The drop-down list of regions should support all available AWS regions in which lambda functions can be deployed. As of today, at least one region **eu-central-2** should be present, possibly more regions.

### Actual Result

The drop-down list is incomplete. I cannot select **eu-central-2**

### Product Area

Settings - Integrations

### Link

*No response*

### DSN

*No response*

### Version

latest

Start in the AWS Lambda Integration settings flow and trace how the region dropdown is populated. Compare its region list with AWS Lambda's available regions, including eu-central-2, and verify that the missing region can be selected after the change.

Written by the indexing model from the issue text.