Update absl and googletest (#18827)
### Description
Update absl and googletest to their latest version to include some cmake
changes:
1. A googletest's cmake change that will allow using external absl and
re2.
2. Nullability enhancements that will allow our clang-based static
analysis detecting many kinds of null pointer errors.
### Motivation and Context
To fix a C4744 link warning in our Windows pipelines.
```
LINK : warning C4744: 'static char const absl::lts_20230802::base_internal::FastTypeTag<bool>::dummy_var' has different type in 'd:\a\_work\_temp\abseil_cpp\abseil-cpp-20230802.0\absl\flags\parse.cc' and 'd:\a\_work\1\b\relwithdebinfo\_deps\googletest-src\googletest\src\gtest-all.cc': 'signed char' and 'unsigned char' [D:\a\_work\1\b\RelWithDebInfo\onnxruntime_mlas_test.vcxproj]
LINK : warning C4744: 'static char const absl::lts_20230802::base_internal::FastTypeTag<class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > >::dummy_var' has different type in 'd:\a\_work\_temp\abseil_cpp\abseil-cpp-20230802.0\absl\flags\parse.cc' and 'd:\a\_work\1\b\relwithdebinfo\_deps\googletest-src\googletest\src\gtest-all.cc': 'signed char' and 'unsigned char' [D:\a\_work\1\b\RelWithDebInfo\onnxruntime_mlas_test.vcxproj]
LINK : warning C4744: 'static char const absl::lts_20230802::base_internal::FastTypeTag<class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > >::dummy_var' has different type in 'd:\a\_work\_temp\abseil_cpp\abseil-cpp-20230802.0\absl\flags\internal\usage.cc' and 'd:\a\_work\1\b\relwithdebinfo\_deps\googletest-src\googletest\src\gtest-all.cc': 'signed char' and 'unsigned char' [D:\a\_work\1\b\RelWithDebInfo\onnxruntime_mlas_test.vcxproj]
LINK : warning C4744: 'static char const absl::lts_20230802::base_internal::FastTypeTag<bool>::dummy_var' has different type in 'd:\a\_work\_temp\abseil_cpp\abseil-cpp-20230802.0\absl\flags\internal\flag.cc' and 'd:\a\_work\1\b\relwithdebinfo\_deps\googletest-src\googletest\src\gtest-all.cc': 'signed char' and 'unsigned char' [D:\a\_work\1\b\RelWithDebInfo\onnxruntime_mlas_test.vcxproj]
LINK : warning C4744: 'static char const absl::lts_20230802::base_internal::FastTypeTag<class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char> > >::dummy_var' has different type in 'd:\a\_work\_temp\abseil_cpp\abseil-cpp-20230802.0\absl\flags\internal\flag.cc' and 'd:\a\_work\1\b\relwithdebinfo\_deps\googletest-src\googletest\src\gtest-all.cc': 'signed char' and 'unsigned char' [D:\a\_work\1\b\RelWithDebInfo\onnxruntime_mlas_test.vcxproj]
LINK : warning C4744: 'static char const absl::lts_20230802::base_internal::FastTypeTag<int>::dummy_var' has different type in 'd:\a\_work\_temp\abseil_cpp\abseil-cpp-20230802.0\absl\flags\internal\flag.cc' and 'd:\a\_work\1\b\relwithdebinfo\_deps\googletest-src\googletest\src\gtest-all.cc': 'signed char' and 'unsigned char' [D:\a\_work\1\b\RelWithDebInfo\onnxruntime_mlas_test.vcxproj]
```
