test: exclude unsupported region for PredictionsTransformerV2 E2E

[atierian]

Problem

The PredictionsTransformerV2Tests E2E test case always passes locally buy has consistently failed in CI for a while now with the error:

    TypeError: Invalid URL
      18 |
      19 |   async query(query: string, variables: any = {}): Promise<GraphQLResponse> {
    > 20 |     const axRes = await axios.post<GraphQLResponse>(
         |                               ^
      21 |       this.url,
      22 |       {
      23 |         query,
      at dispatchHttpRequest (../../node_modules/axios/lib/adapters/http.js:232:20)
      at ../../node_modules/axios/lib/adapters/http.js:152:5
      at wrapAsync (../../node_modules/axios/lib/adapters/http.js:132:10)
      at http (../../node_modules/axios/lib/adapters/http.js:170:10)
      at Axios.dispatchRequest (../../node_modules/axios/lib/core/dispatchRequest.js:51:10)
      at Axios._request (../../node_modules/axios/lib/core/Axios.js:173:33)
      at Axios.request (../../node_modules/axios/lib/core/Axios.js:40:25)
      at Axios.httpMethod [as post] (../../node_modules/axios/lib/core/Axios.js:212:19)
      at Function.wrap (../../node_modules/axios/lib/helpers/bind.js:5:15)
      at GraphQLClient.query (src/GraphQLClient.ts:20:31)
      at Object.<anonymous> (src/__tests__/PredictionsTransformerV2Tests.e2e.test.ts:173:41)

This happens because our current e2e_workflow.yml has this test running in ap-northeast-3 (reference), a region unsupported by Amazon Rekognition (reference).

The deployment fails and the GraphQL endpoint is invalid.

Description of changes

Updates scripts/split-e2e-tests.ts to prevent PredictionsTransformerV2Tests from running in ap-northeast-3. This is done by:

• Forcing PredictionsTransformerV2Tests to run by itself.
• Adding a TEST_REGION_EXCLUSIONS map that removes excluded regions from the candidate regions.

CDK / CloudFormation Parameters Changed

N/A

Issue #, if available

Related docs PR

• add region callout for gen1 predictions directive docs#8111

Description of how you validated changes

• E2E test run

Checklist

• PR description included
• yarn test passes
• E2E test run linked
• Tests are changed or added
• Relevant documentation is changed or added (and PR referenced)
• New AWS SDK calls or CloudFormation actions have been added to relevant test and service IAM policies
• Any CDK or CloudFormation parameter changes are called out explicitly

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.