Drop support for Python 3.7

What's Changed

• Upgrade dependencies by @bneijt in #59
• Bump cryptography from 40.0.1 to 41.0.3 by @dependabot in #62
• Upgrade poetry by @bneijt in #63
• OSV scan by @bneijt in #54
• Update install instructions by @bneijt in #64
• Remove reference to pkg_resources by @bneijt in #65

Full Changelog: 0.4.5...0.4.6