Update go.mod dependencies and Go version

[Copilot]

This PR updates the Go module dependencies and Go version to their latest stable releases.

Changes Made

Go Version Update

• Go: 1.24.1 → 1.24.5

Dependency Updates

• golang.org/x/tools: v0.31.0 → v0.35.0
• golang.org/x/mod: v0.24.0 → v0.26.0 (indirect)
• golang.org/x/sync: v0.12.0 → v0.16.0 (indirect)
• rsc.io/script: v0.0.2 (no update available)

Additional Improvements

• Added rdeadcode binary to .gitignore to prevent accidental commits of build artifacts
• Removed accidentally committed binary from repository

Verification

All updates have been thoroughly tested:

• ✅ Project builds successfully with go build
• ✅ All tests pass with go test ./...
• ✅ Code passes go vet static analysis
• ✅ Code formatting verified with go fmt
• ✅ CLI functionality confirmed working

Benefits

• Security: Latest dependency versions include security patches and bug fixes
• Performance: Newer versions may include performance improvements
• Compatibility: Keeps the project up-to-date with the Go ecosystem
• Maintenance: Reduces technical debt by staying current with dependencies

The updates are backward compatible and do not introduce any breaking changes to the public API.

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