Update CI workflow configuration to use go-version-file

[Copilot]

Updates all GitHub Actions CI workflows to use go-version-file: 'go.mod' instead of hardcoded Go version numbers, ensuring consistency with the project's Go version requirements.

Changes Made

• lint.yaml: Changed from go-version: "1.25" to go-version-file: 'go.mod'
• test.yaml: Changed from go-version: "1.25" to go-version-file: 'go.mod'
• release.yaml: Changed from go-version: 1.25 to go-version-file: 'go.mod' and upgraded actions/setup-go from v4 to v5 for consistency

Benefits

• CI workflows automatically use the Go version specified in go.mod (currently 1.25.5)
• No manual updates needed when Go version changes in go.mod
• Consistent action versions across all workflows
• Reduced maintenance burden

Testing

• ✅ YAML formatting verified with yamlfmt
• ✅ Code review completed with no issues
• ✅ Security scan completed with no vulnerabilities

The changes are minimal and focused on improving CI configuration maintainability.

Original prompt

Reference: https://github.com/rapjul/panforge/actions/runs/21119638100/job/60730391772#step:4:1

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[rapjul]

@copilot Please retry.

[Copilot]

@copilot Please retry.

Done! I've updated all CI workflow files to use go-version-file: 'go.mod' instead of hardcoded version numbers. This ensures consistency and automatically uses the Go version specified in go.mod (1.25.5). Also updated release.yaml to use actions/setup-go@v5 for consistency with other workflows. Changes committed in 0f64c5d.