gRPC Swift 1.23.1

SemVer Patch

• Swift 6-ify the package manifest (#1955)
• Fix warnings in SwiftPM plugin (#1958)
• Update to protobuf 1.27.0 (#1973)
• Improve error message for missing reflection data (#2038)
• Use SwiftProtobuf's new CodeGenerator interface (#2043)
• Stop using deprecated protobuf API (#2045)
• Bump version number to 1.23.1 (#2062)

Other Changes

• Manually cleanup unix domain socket path in NIOTS test (#1951)
• Add integ test for SwiftPM plugin (#1956)
• Move v1 examples to v1 subdirectory (#1963)
• Update test certs (#1966)
• Fix broken symlinks (#1988)
• Update test certs (#1998)
• Fix tests to work with unreleased swift-nio changes (#2001)
• Add check that generated code is up-to-date (#2013)
• Add docc docs for grpc core (#2016)
• Use Swift 6 to build docs on Swift Package Index (#2020)
• Move examples to top-level (#2024)
• Regenerate protos (#2039)
• Update plugin bundling script (#2053)