fix: eliminate @aws-sdk/core 3.775.0 and 3.810.0 from yarn.lock

Remove stale lockfile entries for @aws-sdk packages in the 3.775.x and
3.810.x version families that declared fast-xml-parser 4.4.1. These came
from aws-appsync@4.1.10 (via @aws-sdk/client-s3@^3.25.0 resolved to
3.779.0) and @aws-cdk/toolkit-lib@1.16.0 (via @aws-sdk/client-*@^3
resolved to 3.810.0).

After removal, yarn install re-resolved these ranges to the latest
compatible versions which use @aws-sdk/core >= 3.974.8 (no fast-xml-parser
dependency).

Remaining: @aws-sdk/core@3.622.0 from @aws-amplify/ai-constructs@1.6.1
still declares fast-xml-parser 4.4.1, but the resolution forces it to
5.5.12. This will be addressed separately.

Author: Simone319