Doc preview: f36458a apply `us-east-1` as default region if not set by user in `with_test_defaults_v2()` (#4312)

AWS Services

• aws_sdk_dynamodb
• aws_sdk_sso
• aws_sdk_ssooidc
• aws_sdk_sts
• aws_sdk_transcribestreaming

AWS Runtime Crates

• aws_config
• aws_credential_types
• aws_runtime
• aws_runtime_api
• aws_sigv4
• aws_types

Smithy Runtime Crates

• aws_smithy_async
• aws_smithy_cbor
• aws_smithy_checksums
• aws_smithy_compression
• aws_smithy_dns
• aws_smithy_eventstream
• aws_smithy_experimental
• aws_smithy_http
• aws_smithy_http_client
• aws_smithy_http_server
• aws_smithy_http_server_python
• aws_smithy_http_server_typescript
• aws_smithy_json
• aws_smithy_mocks
• aws_smithy_observability
• aws_smithy_observability_otel
• aws_smithy_protocol_test
• aws_smithy_query
• aws_smithy_runtime
• aws_smithy_runtime_api
• aws_smithy_types
• aws_smithy_types_convert
• aws_smithy_wasm
• aws_smithy_xml

Bold indicates a runtime crate had changes since the base revision 5e50dfe Run `cargo update` on the runtime lockfiles and the SDK lockfile (#4336). These may or may not be documentation changes.