Fix Issue 23572 - OpenBSD: Add OpenBSD to the RTLD_DEFAULT list

[ibara]

No description provided.

[dlang-bot]

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Bugzilla references

Auto-close	Bugzilla	Severity	Description
✓	23572	major	OpenBSD: Add OpenBSD to the RTLD_DEFAULT list

Testing this PR locally

If you don't have a local development environment setup, you can use Digger to test this PR:

dub run digger -- build "master + dmd#14725"

[ibara]

Looks like one of the required Azure pipelines failed. Though I can't imagine it would be as a result of this diff.