Several tests fail on FreeBSD

### Describe the bug, including details regarding any error messages, version, and platform.

Test errors:

```
[ RUN ] TestMemoryMappedFile.MapPartFile
/usr/ports/databases/arrow/work/apache-arrow-19.0.1/cpp/src/arrow/io/file_test.cc:633: Failure
Failed
Expected 'MemoryMappedFile::Open(path, FileMode::READWRITE, unalign_offset, 4096)' to fail with IOError, but got OK

[ FAILED ] TestMemoryMappedFile.MapPartFile (0 ms)
```

```
[ RUN ] FileUtils.LongPaths
/usr/ports/databases/arrow/work/apache-arrow-19.0.1/cpp/src/arrow/util/io_util_test.cc:1006: Failure
Failed
'_error_or_value85.status()' failed with IOError: Cannot create directory 'xxx-io-util-test-dir-long/123456789ABCDEF/123456789ABCDEF/123456789ABCDEF/123456789ABCDEF/123456789ABCDEF/123456789ABCDEF/123456789ABCDEF/123456789ABCDEF/123456789ABCDEF/123456789ABCDEF/123456789ABCDEF/123456789ABCDEF/123456789ABCDEF/123456789ABCDEF/123456789ABCDEF/123456789ABCDEF/123456789ABCDEF/123456789ABCDEF/123456789ABCDEF/123456789ABCDEF/123456789ABCDEF/123456789ABCDEF/123456789ABCDEF/123456789ABCDEF/123456789ABCDEF/123456789ABCDEF/123456789ABCDEF/123456789ABCDEF/123456789ABCDEF/123456789ABCDEF/123456789ABCDEF/123456789ABCDEF/123456789ABCDEF/123456789ABCDEF/123456789ABCDEF/123456789ABCDEF/123456789ABCDEF/123456789ABCDEF/123456789ABCDEF/123456789ABCDEF/123456789ABCDEF/123456789ABCDEF/123456789ABCDEF/123456789ABCDEF/123456789ABCDEF/123456789ABCDEF/123456789ABCDEF/123456789ABCDEF/123456789ABCDEF/123456789ABCDEF/123456789ABCDEF/123456789ABCDEF/123456789ABCDEF/123456789ABCDEF/123456789ABCDEF/123456789ABCDEF/123456789ABCDEF/123456789ABCDEF/123456789ABCDEF/123456789ABCDEF/123456789ABCDEF/123456789ABCDEF/123456789ABCDEF/123456789ABCDEF'. Detail: [errno 63] File name too long

[ FAILED ] FileUtils.LongPaths (0 ms)
```

```
[ RUN ] TestParquetStatistics.NullMax
/usr/ports/databases/arrow/work/apache-arrow-19.0.1/cpp/src/arrow/dataset/file_parquet_test.cc:835: Failure
Failed
'_error_or_value233.status()' failed with Key error: environment variable undefined

[ FAILED ] TestParquetStatistics.NullMax (0 ms)
```

Version: 19.0.1
clang-19
FreeBSD 14.2

### Component(s)

C++