Upgrade Go to 1.27.1 and modernize linting

[rajpreet-s]

Upgrades the CLI's Go toolchain from 1.23 to 1.27.1 across the module, CI workflows, and Docker images. Migrates golangci-lint to v2 (required for Go 1.27.1 compatibility) and fixes all errcheck, bodyclose, and gosec findings surfaced by the upgraded linter.

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Changes

Go Version Upgrade

• go.mod & CONTRIBUTING.md: Updated go 1.23.0 → go 1.27.1 and updated documented contributor requirements.

CI & Docker

• test.yml, release.yml, debricked.yml: Pinned all actions/setup-go steps to 1.27.1.
• alpine.Dockerfile, debian.Dockerfile: Bumped Docker base images to golang:1.27.1-*.
• Workflow Actions: Upgraded golangci-lint install step to v2.13.2 and updated to the /v2 module path.

golangci-lint v1 → v2 Migration (.golangci.yml)

• Migrated configuration to schema version: "2" (resolves Go 1.27.1 export data decode failures on v1.62.2).
• Moved goimports and gofmt under the formatters: section.
• Removed obsolete typecheck entry and duplicate staticcheck entry.
• Re-enabled silently broken linters: errcheck, bodyclose, and gosec.

Linter Fixes

• errcheck: Handled previously ignored error returns (Close(), Remove(), RemoveAll(), Setenv(), Fprintf()) across ~20 files in auth, callgraph, client, fingerprint, io, report, resolution, and upload.
• bodyclose: Explicitly closed HTTP response body in batch.go.
• gosec:
  • Tightened directory permissions (0755 → 0750) in 3 locations.
  • Sanitized log outputs to prevent log-line injection.
  • Added justified #nosec annotations for CLI-necessary operations (opening user files, executing git, maven, gradle).

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Known Follow-ups

Tracked via TODO comments in .golangci.yml:

• goconst: Kept disabled due to pre-existing repeated string literals.
• staticcheck: Excluded pre-existing style/naming rules surfaced by v2 (ST1005, ST1006, ST1012, ST1019, QF1003, QF1004, QF1009, QF1012).

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Testing

• Build: go build succeeds under Go 1.27.1.
• Lint: golangci-lint run reports 0 issues.
• Docker: Alpine and Debian Docker images build and execute successfully.
• Unit Tests: All runnable unit tests pass (unrelated environment gaps like missing Maven, .NET, Composer, pip cause pre-existing failures).