Release v0.59.0

Added

• A new experimental 'join' mode. This mode runs multiple Semgrep rules
  on a codebase and "joins" the results based on metavariable contents. This
  lets users ask questions of codebases like "do any 3rd party
  libraries use a dangerous function, and do I import that library directly?" or
  "is this variable passed to an HTML template, and is it rendered in that template?"
  with several Semgrep rules.

Fixed

• Improve location reporting of errors
• metavariable-pattern: pattern-not-regex now works (#3503)
• Rust: correctly parse macros (#3513)
• Python: imports are unsugared correctly (#3940)
• Ruby: pattern: $X in the presence of interpolated strings now works (#3560)