Add linkcheck option to ignore httpredirect warnings

[ppcano]

The make linkcheck command in the unit tests / docs CI job was failing because some URLs were redirected:

That's it. 186 links in 188 URLs checked. 2 warnings found. 0 errors found.
Stopped checking at 2025-02-10 11:10:04+000 (22 seconds)
make: *** [linkcheck] Error 1


Exit Code: 2

Since redirects shouldn’t be considered failures, this PR adds the ignorewarnings=http-redirected option to suppress httpredirect failures.

With this change, the make linkcheck output now displays:

That's it. 186 links in 188 URLs checked. 0 warnings found. 0 errors found.
Stopped checking at 2025-02-10 11:11:12+000 (28 seconds)

Exit Code: 0

[github-actions]

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