Fix issue 23324 - Incorrect source link in std.format docs

[pbackus]

No description provided.

[dlang-bot]

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Bugzilla references

Auto-close	Bugzilla	Severity	Description
✓	23324	normal	Incorrect source link in std.format docs

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 + phobos#8556"

[wolframw]

Any idea why the bot isn't updating the Bugzilla issue?