Remove `enableNewCrateOrganizationScheme` codegen flag (#2507)

CHANGELOG.next.toml

...oftware/amazon/smithy/rustsdk/AwsFluentClientDecorator.kt

.../software/amazon/smithy/rustsdk/AwsPresigningDecorator.kt

...n/kotlin/software/amazon/smithy/rustsdk/AwsRuntimeType.kt

.../software/amazon/smithy/rustsdk/BaseRequestIdDecorator.kt

...lin/software/amazon/smithy/rustsdk/CredentialProviders.kt

.../kotlin/software/amazon/smithy/rustsdk/RegionDecorator.kt

...tlin/software/amazon/smithy/rustsdk/UserAgentDecorator.kt

...rc/test/kotlin/software/amazon/smithy/rustsdk/TestUtil.kt

buildSrc/src/main/kotlin/CodegenTestCommon.kt

...smithy/rust/codegen/client/smithy/ClientCodegenVisitor.kt

...zon/smithy/rust/codegen/client/smithy/ClientRustModule.kt

...n/smithy/rust/codegen/client/smithy/ClientRustSettings.kt

...degen/client/smithy/customizations/ClientDocsGenerator.kt

...codegen/client/smithy/customize/RequiredCustomizations.kt

...t/codegen/client/smithy/generators/ClientEnumGenerator.kt

...st/codegen/client/smithy/generators/PaginatorGenerator.kt

...mithy/generators/client/CustomizableOperationGenerator.kt

.../client/smithy/generators/client/FluentClientGenerator.kt

...ent/smithy/generators/protocol/ClientProtocolGenerator.kt