[S3 Plugin] DTH S3 Plugin can not deploy in GovCloud due to missing assets

[YikaiHu]

Describe the bug
DTH S3 Plugin can not deploy in GovCloud due to missing assets.

Should add aws-us-gov mapping in CloudFormation assets mappings.

"Mappings": {
    "FinderStackAssetTableC56DDAEC": {
      "aws": {
        "assetDomain": "https://aws-gcr-solutions-assets.s3.amazonaws.com/"
      },
      "aws-cn": {
        "assetDomain": "https://aws-gcr-solutions-assets.s3.cn-northwest-1.amazonaws.com.cn/"
      },
      "aws-us-gov": {
        "assetDomain": "https://aws-gcr-solutions-assets.s3.amazonaws.com/"
      }
    },

To Reproduce
Deploy S3 Plugin in GovCloud

Expected behavior
Deployment successful.

Please complete the following information about the solution:

• Version: [v2.6.0]

To get the version of the solution, you can look at the description of the created CloudFormation stack. For example, "(SO8001) - Data Transfer Hub with aws-solutions-constructs: This template deploys an one-stop toolset for transferring data from different sources into AWS. Template version v1.0.0".

• Region: [us-gov-west-1/us-gov-east-1]

Screenshots
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Additional context
Add any other context about the problem here.

[YikaiHu]

Workaround: please using this patching template.

DataTransferS3Stack-gc-patch.json

We will fix this issue in next release.

[YikaiHu]

Fixed in v2.6.0