CI: Update code signing certificates

[derrod]

Description

Update code signing cert.

As usual, this will require a merge commit to maintain the commit hash for the workflow.

The public key remains the same, so we do not expect any issues with anti-cheat solutions, but we will be monitoring for issues.

Motivation and Context

DigiCert is making some changes, including revoking one of their intermediaries, requiring certificates to be re-issued to produce valid signatures after May 2026: https://knowledge.digicert.com/alerts/digicert-transitioning-multipurpose-pki-hierarchies-to-dedicated-tls-root-hierarchies

Note that since all our signatures are timestamped, signatures on old releases should remain valid.

How Has This Been Tested?

N/A

Types of changes

• Tweak (non-breaking change to improve existing functionality)

Checklist:

• My code has been run through clang-format.
• I have read the contributing document.
• My code is not on the master branch.
• The code has been tested.
• All commit messages are properly formatted and commits squashed where appropriate.
• I have included updates to all appropriate documentation.