roxctl: update checksum for 4.9.3 release

[stefanb]

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• Have you checked that there aren't other open pull requests for the same formula update/change?
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Noticed in

• go 1.26.0, [email protected] 1.25.7 (new formula) #258912

[stefanb]

Duplicate of

• roxctl: update checksum for 4.9.3 rel #266997