[Xcode] Add CMAKE_POLICY_VERSION_MINIMUM for CMake 4.x compatibility

CMake 4.x (shipped with Xcode 26.3) removed compatibility with
cmake_minimum_required versions below 3.5. The AWS CRT submodule
still uses an older minimum version, causing the configure phase
to fail. Adding -DCMAKE_POLICY_VERSION_MINIMUM=3.5 allows the
build to proceed without modifying upstream cmake files.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: falken42

hyperdrive/aws-sdk-cpp.xcodeproj/project.pbxproj

@@ -84,7 +84,7 @@
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 			shellPath = /bin/zsh;
-			shellScript = "AWSSDKCPP_CLIENTS=\"lambda;s3\"\nAWSSDKCPP_BUILD_DIR=${TARGET_BUILD_DIR}/aws-sdk-cpp\ncd ${AWSSDKCPP_BUILD_DIR} ; cmake ${PROJECT_DIR}/.. -DCMAKE_BUILD_TYPE=\"Release\" -DTARGET_ARCH=APPLE -DCMAKE_OSX_DEPLOYMENT_TARGET=\"10.13\" -DCMAKE_OSX_ARCHITECTURES=\"x86_64;arm64\" -DBUILD_ONLY=\"${AWSSDKCPP_CLIENTS}\" -DBUILD_SHARED_LIBS=OFF -DENABLE_RTTI=OFF -DENABLE_TESTING=OFF -DENABLE_ADDRESS_SANITIZER=OFF -DENABLE_SANITIZERS=OFF -DHAS_SANITIZERS=OFF -DENABLE_UNITY_BUILD=ON -DMINIMIZE_SIZE=ON\n";
+			shellScript = "AWSSDKCPP_CLIENTS=\"lambda;s3\"\nAWSSDKCPP_BUILD_DIR=${TARGET_BUILD_DIR}/aws-sdk-cpp\ncd ${AWSSDKCPP_BUILD_DIR} ; cmake ${PROJECT_DIR}/.. -DCMAKE_BUILD_TYPE=\"Release\" -DCMAKE_POLICY_VERSION_MINIMUM=3.5 -DTARGET_ARCH=APPLE -DCMAKE_OSX_DEPLOYMENT_TARGET=\"10.13\" -DCMAKE_OSX_ARCHITECTURES=\"x86_64;arm64\" -DBUILD_ONLY=\"${AWSSDKCPP_CLIENTS}\" -DBUILD_SHARED_LIBS=OFF -DENABLE_RTTI=OFF -DENABLE_TESTING=OFF -DENABLE_ADDRESS_SANITIZER=OFF -DENABLE_SANITIZERS=OFF -DHAS_SANITIZERS=OFF -DENABLE_UNITY_BUILD=ON -DMINIMIZE_SIZE=ON\n";
 			showEnvVarsInLog = 0;
 		};
 		50F4BA9F4BD39E776B2D3EC9 /* Copy generated headers into source tree */ = {