Fix bdls_filesystemutil test driver
Fix bdls_filesystemutil test driver

This pull request removes a test vector from the test case for `bdls::FilesystemUtil::getLastModificationTime`, which inadvertently would invoke `bdlt::Datetime` comparison operators with an operand having an "hour" field with the value `24`, which is undefined behavior.
bloomberg/bde,bloomberg/bde,bloomberg/bde,bloomberg/bde,bloomberg/bde