ports-mgmt/pkg: update to 1.21.0

Changes since latest 1.20.0

• new event PKG_EVENT_PKG_ERRNO
• add: only generates .pkgsave when really needed
• repo:
  • remove the ability to create v1 repository format
  • remove ability to produce meta.{pkg,txz} unused since 1.13
  • replace packagesite.pkg with data.pkg (new extensible format)
  • keep producing packagesite.pkg for backward compatibility
  • local repository information is now located in /var/dbv/repos/<reponame/*
• support job cancellation (packagekit support)
• update bundle code to latest versions:
  • libcurl
  • sqlite
  • lua
  • libucl
• plist keywords:
  • new @override_prefix
  • new @var key value (able to expand %%key%%)
• scripts:
  • new variable PKG_ISCHROOTED for script to be aware if being run bia pkg -c
• update:
  • prevents concurrent pkg update to compete
• pkgbase:
  • .snap now comes after .alpha in versionning
• key:
  • new subcommand to be able to generate signature keys
• signatures:
  • add support ECDSA and EdDSA for all its signature mechanism
• elfhints:
  • pkg now supports elfhints of any byte-order on FreeBSD
• solver:
  • prevent directly in the solver the ability to remove vital or locked packages

PR: 277978
Exp-run: antoine