reposurgeon: update checksum for 5.9 release

[stefanb]

Ref:

• go 1.27rc2, go@1.26 1.26.5 (new formula) #288803

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• Have you ensured that your commits follow the commit style guide?
• Have you checked that there aren't other open pull requests for the same formula update/change?
• Have you built your formula locally with HOMEBREW_NO_INSTALL_FROM_API=1 brew install --build-from-source <formula>?
• Is your test running fine brew test <formula>?
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• AI was used to generate or assist with generating this PR. Please specify below how you used AI to help you, and what steps you have taken to manually verify the changes.

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[daeho-ro]

• https://gitlab.com/esr/reposurgeon/-/work_items/459