Add parallel execution capability for C++ unit tests using GTest
sharding, enabling faster CI feedback while maintaining test isolation.
Changes:
- Add run_cpp_ut.sh: New script for parallel UT execution without
coverage
- Update run_cpp_codecov.sh: Add optional parallel support (disabled by
default)
- Add GetTestTempBasePath/GetTestTempPath helpers for shard-specific
temp paths
- Initialize ArrowFileSystemSingleton in test global setup
- Fix flaky ThreadLocalGEOSContextTest with synchronization barrier
- Update test files to use dynamic temp paths instead of hardcoded /tmp/
The coverage script (run_cpp_codecov.sh) defaults to sequential mode for
accurate coverage data. The new run_cpp_ut.sh script defaults to
parallel mode (3 shards) for fast CI feedback.
Signed-off-by: Zhikun Yao <zhikun.yao@zilliz.com>