Fix the FreeBSD CI

[jvoisin]

The FreeBSD CI has been broken for weeks:

[LOG][17408](src/iso_alloc_profiler.c:56 _iso_alloc_print_stats()) RSS: 22 (mb)
[LOG][17408](src/iso_alloc_profiler.c:60 _iso_alloc_print_stats()) Soft Page Faults: 6307
[LOG][17408](src/iso_alloc_profiler.c:61 _iso_alloc_print_stats()) Hard Page Faults: 0
... Succeeded
Running wild_free test
[ABORTING][17410](src/iso_alloc.c:1676 _iso_free_internal_unlocked()) Could not find any zone for allocation at 0x7fffffffffff
... Succeeded
Running unaligned_free test
[ABORTING][17412](src/iso_alloc.c:1386 iso_free_chunk_from_zone()) Chunk at 0x336857eb1801 of zone[7] is not 8 byte aligned
... Succeeded
Running incorrect_chunk_size_multiple test
[ABORTING][17414](src/iso_alloc.c:1399 iso_free_chunk_from_zone()) Chunk at 0x24db8c320840 is not a multiple of zone[7] chunk size 2048. Off by 64 bits
... Succeeded
Running big_canary_test test
[ABORTING][17416](src/iso_alloc.c:1324 check_big_canary()) Big zone 0x168afee65ef0 bottom canary has been corrupted! Value: 0x4141414141414141 Expected: 0x186927f8d579f37c
... Succeeded
Running zero_alloc test
... Succeeded
Running sized_free test
[ABORTING][17420](src/iso_alloc.c:1596 _iso_free_size()) Invalid size (expected 2048, got 4096) for chunk 0xa1f8843f800
... Succeeded
gmake: *** [Makefile:325: tests] Error 255

Exit status: 2

[struct]

In some of the recent PRs the failure is here:

Running interfaces_test test
[ABORTING][17392](tests/interfaces_test.c:91 main()) iso_strdup failed
... Failed

... but unclear to me why exactly. That being said I don't think this is always where or why it fails. This CI just seems very flakey.

[jvoisin]

If the problem was easy to pinpoint, I would have opened a pull-request instead of an issue :P

[devnexen]

CI might not be so flakey after all, tests fail the same on a real freebsd instance. I suspect some system settings need to be adjusted (via sysctl) but not sure yet.

[struct]

Updated to a newer FreeBSD in CI #234