[Sync] Update project files from source repository (f7c6655)

[mrz1836]

What Changed

• Updated actions/checkout from commit de0fac2e4500dabe0009e67214ff5f5447ce83dd (v6.0.2) to commit df4cb1c069e1874edd31b4311f1884172cec0e10 (v6.0.3) across 21 workflow and action files
• Updated GOVULNCHECK_GO_VERSION from 1.26.3 to 1.26.4 in .github/env/00-core.env
• Changes applied consistently across all GitHub Actions workflows including fortress-benchmarks, codeql-analysis, dependabot-auto-merge, fortress-pre-commit, fortress-release, fortress-coverage, fortress-code-quality, auto-merge-on-approval, fortress-completion-report, fortress-security-scans, fortress-setup-config, fortress-test-fuzz, fortress-test-matrix, fortress-warm-cache, fortress-test-suite, pull-request-management, stale-check, scorecard, sync-labels, and the warm-cache action

Why It Was Necessary

• Keeps GitHub Actions dependencies up to date with the latest v6.0.3 release of the checkout action for security patches and bug fixes
• Updates the govulncheck Go version to 1.26.4 to ensure vulnerability scanning uses the latest Go toolchain with recent security fixes
• Maintains consistency across all CI/CD workflows by applying the same version updates uniformly

Testing Performed

• Version updates to actions/checkout v6.0.3 will be validated automatically when CI workflows execute on this PR
• The govulncheck Go version update will be tested during security scanning workflow execution
• All existing workflow tests and checks will verify compatibility with the updated action and Go versions

Impact / Risk

• Low Risk: Patch version updates (v6.0.2 → v6.0.3 and Go 1.26.3 → 1.26.4) typically contain only bug fixes and security patches without breaking changes
• No Breaking Changes: The checkout action v6.0.3 and Go 1.26.4 maintain backward compatibility with previous patch versions
• Positive Impact: Ensures CI/CD pipeline benefits from latest security fixes and improvements in both the checkout action and Go toolchain

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[mrz1836]

LGTM!