Allow using a different version of flatbuffers when building with vcpkg (#23946)

### Description
Allow using a different version of flatbuffers when building with vcpkg,
so that users do not need to pin flatbuffer's version, which provides
more flexibility in the build process.

Delete utf8_range from the dependencies, because it is an indirect
dependency of protobuf, which is already included in the build process.
### Motivation and Context

Author: snnn

cmake/deps.txt

@@ -53,7 +53,6 @@ re2;https://github.com/google/re2/archive/refs/tags/2024-07-02.zip;646e1728269cd
 safeint;https://github.com/dcleblanc/SafeInt/archive/refs/tags/3.0.28.zip;23f252040ff6cb9f1fd18575b32fa8fb5928daac
 tensorboard;https://github.com/tensorflow/tensorboard/archive/373eb09e4c5d2b3cc2493f0949dc4be6b6a45e81.zip;67b833913605a4f3f499894ab11528a702c2b381
 cutlass;https://github.com/NVIDIA/cutlass/archive/refs/tags/v3.5.1.zip;e49b2b964163d27765a5002d210a2f3c73771835
-utf8_range;https://github.com/protocolbuffers/utf8_range/archive/72c943dea2b9240cd09efde15191e144bc7c7d38.zip;9925739c9debc0efa2adcb194d371a35b6a03156
 extensions;https://github.com/microsoft/onnxruntime-extensions/archive/c24b7bab0c12f53da76d0c31b03b9f0f8ec8f3b4.zip;239063aee4946a9af147b473a4c3da78ba7413b4
 composable_kernel;https://github.com/ROCmSoftwarePlatform/composable_kernel/archive/204da9c522cebec5220bba52cd3542ebcaf99e7a.zip;1827348efd47831c13074245274d41b7cae8a557
 directx_headers;https://github.com/microsoft/DirectX-Headers/archive/refs/tags/v1.613.1.zip;47653509a3371eabb156360f42faf582f314bf2e

cmake/external/onnxruntime_external_deps.cmake

@@ -107,23 +107,6 @@ if(onnxruntime_USE_MIMALLOC)
   FetchContent_MakeAvailable(mimalloc)
 endif()
 
-#Protobuf depends on utf8_range
-onnxruntime_fetchcontent_declare(
-    utf8_range
-    URL ${DEP_URL_utf8_range}
-    URL_HASH SHA1=${DEP_SHA1_utf8_range}
-    EXCLUDE_FROM_ALL
-    FIND_PACKAGE_ARGS NAMES utf8_range
-)
-
-set(utf8_range_ENABLE_TESTS OFF CACHE BOOL "Build test suite" FORCE)
-set(utf8_range_ENABLE_INSTALL OFF CACHE BOOL "Configure installation" FORCE)
-
-# The next line will generate an error message "fatal: not a git repository", but it is ok. It is from flatbuffers
-onnxruntime_fetchcontent_makeavailable(utf8_range)
-# protobuf's cmake/utf8_range.cmake has the following line
-include_directories(${utf8_range_SOURCE_DIR})
-
 # Download a protoc binary from Internet if needed
 if(NOT ONNX_CUSTOM_PROTOC_EXECUTABLE AND NOT onnxruntime_USE_VCPKG)
   # This part of code is only for users' convenience. The code couldn't handle all cases. Users always can manually
@@ -442,6 +425,9 @@ target_include_directories(safeint_interface INTERFACE ${safeint_SOURCE_DIR})
 
 
 # Flatbuffers
+if(onnxruntime_USE_VCPKG)
+  find_package(flatbuffers REQUIRED)
+else()
 # We do not need to build flatc for iOS or Android Cross Compile
 if (CMAKE_SYSTEM_NAME STREQUAL "iOS" OR CMAKE_SYSTEM_NAME STREQUAL "Android" OR CMAKE_SYSTEM_NAME STREQUAL "Emscripten")
   set(FLATBUFFERS_BUILD_FLATC OFF CACHE BOOL "FLATBUFFERS_BUILD_FLATC" FORCE)
@@ -492,6 +478,7 @@ namespace std { using ::getenv; }
     endif()
   endif()
 endif()
+endif()
 
 # ONNX
 if (NOT onnxruntime_USE_FULL_PROTOBUF)