fix(dynamodb): table v2 arn validation (#38354)

[wasim-builds]

Fixes #38354

Problem

TableV2 ARN validation uses a broad Token.isUnresolved check that rejects partial-tokenized ARNs. This breaks cross-account replica validation when the account/region is still a token during synthesis.

Fix

Remove the blanket Token.isUnresolved guard and allow concrete account/region resolution during replica validation.

Scope

• packages/aws-cdk-lib/aws-dynamodb/lib/table-v2.ts: relax validation logic
• packages/aws-cdk-lib/aws-dynamodb/test/table-v2.test.ts: add 15 lines of replica validation tests

Verification

Cross-account table replica creation succeeds when account/region tokens are present but resolvable.

[aws-cdk-automation]

(This review is outdated)

[wasim-builds]

Exemption Request: This fixes a bug in cross-account replica table validation for partially tokenized ARNs. No new AWS resources are introduced.

[wasim-builds]

Rebased onto latest upstream/main and removed unrelated stacked commits. Only dynamodb-specific changes remain:

• fix(dynamodb): always parse Table ARN components during TableV2 cross-account validation
• test(dynamodb): add test for partially tokenized ARN in TableV2MultiAccountReplica

✅ Updated pull request passes all PRLinter validations. Dismissing previous PRLinter review.

[wasim-builds]

Hey 👋 Friendly ping on this one — fixes cross-account replica table ARN validation in DynamoDB TableV2. The change is small and focused. Would appreciate a review when possible! 🙏