* feat: add goanalysis package for nogo
Add goanalysis package providing a standard
golang.org/x/tools/go/analysis.Analyzer for gosec. Enables
integration with nogo, and go vet.
- Implements analysis.Analyzer interface
- Reuses SSA built by analysis framework for efficient caching
- Configurable severity/confidence filtering via flags
- Includes CWE IDs in diagnostics ([CWE-XXX] format)
- Runs both AST rules and SSA analyzers
- Respects #nosec and suppression directives
Also exclude testdata from security scanning in Makefile to
prevent false positives on intentionally vulnerable test files.
* Also exclude testdata from github action
