Bump mini_racer from 0.4.0 to 0.5.0

Bumps mini_racer from 0.4.0 to 0.5.0.

Changelog

Sourced from mini_racer's changelog.

• 11-04-2021

Commits

• d9f890c Bump version
• 33e90ab Avoid compile warnings
• 8bd860b Update to use libv8-node 16.x (#210)
• 6c7abc4 FIX: use rb_str_intern for symbol support
• 05c27e8 DEV: bump required ruby version to >= 2.6 (#214)
• 496f829 Fix sign-extension in Isolate Data (#213)
• 50c3664 False positive on OOM error (#212)
• 7de7a90 CI: Attempt to use rvm-installed Bundler, RubyGems (#207)
• dbf13aa gemspec: Drop configuration for executables (#205)
• ecacd20 CI: Drop 2.4 from the build matrix (#206)
• Additional commits viewable in compare view