chore(deps): bump aws-sdk-swift from 1.7.27 to 1.7.53 (#4262)

Updates the aws-sdk-swift dependency to 1.7.53, which moves the
transitive dependency:

  smithy-swift  0.223.0 -> 0.238.0

aws-crt-swift stays resolved at 0.64.1: smithy-swift raised its floor
from `from: "0.63.0"` to `from: "0.64.0"`, which the already-pinned
0.64.1 satisfies. No other transitive pins change.

The aws-sdk-swift range is almost entirely API and endpoint model
regeneration. For the services Amplify depends on the changes are
additive only: Cognito Identity Provider gains GetProvisionedLimit /
UpdateProvisionedLimit, EumsSms in SmsConfigurationType, and
AdminGetUserAuthFactors; CloudWatch Logs gains storage-tier and
lookup-table APIs; TranscribeStreaming gains an optional
TranscriptFormat parameter. The one breaking entry in the range
(1.7.28 removes SimSpaceWeaver, Panorama, IoT Events, IoT Events Data)
does not touch any Amplify dependency.

smithy-swift's breaking changes in 0.224.0-0.238.0 are confined to the
@_spi(SchemaBasedSerde) codegen surface that only the SDK's own
generated code consumes: ShapeDeserializer.readInteger/readLong
narrowing to Int32/Int64, readDocument returning `any SmithyDocument`,
and ReadStructConsumer being replaced by a deserializeMember
requirement. The modules Amplify imports directly - SmithyIdentity,
SmithyRetries, SmithyHTTPAuth and their API variants - are unchanged.
ClientRuntime's only behavioral delta is percent-encoding moving its
implementation into SmithyHTTPAPI.URLEncodingUtils with the same
allowed character sets.

Verified that the non-sparse-map null regression which gated the
previous bump (#4234) has not returned: SmithyJSON's Deserializer
still compacts UnexpectedNullError out of non-sparse maps and lists,
so Cognito RespondToAuthChallenge responses carrying a null
ChallengeParameters value (e.g. "FRIENDLY_DEVICE_NAME": null in the
SELECT_MFA_TYPE challenge) continue to deserialize.

Author: harsh62

Package.resolved

@@ -9,7 +9,7 @@ let platforms: [SupportedPlatform] = [
     .watchOS(.v9)
 ]
 let dependencies: [Package.Dependency] = [
-    .package(url: "https://github.com/awslabs/aws-sdk-swift", exact: "1.7.27"),
+    .package(url: "https://github.com/awslabs/aws-sdk-swift", exact: "1.7.53"),
     .package(url: "https://github.com/stephencelis/SQLite.swift.git", exact: "0.15.4"),
     .package(url: "https://github.com/mattgallagher/CwlPreconditionTesting.git", from: "2.1.0"),
     .package(url: "https://github.com/aws-amplify/amplify-swift-utils-notifications.git", from: "1.1.0")