v1.7.3

Compare with 1.7.2

Fixes

• -version now reports a build time on go install pkg@version builds — such builds embed no vcs.time, receive no -ldflags, and debug.BuildInfo has no timestamp field, so -version printed built unknown; the release pipeline now bakes the version and a UTC timestamp into the source it tags (buildstamp.go, written by knope prepare-release) and reports it when the resolved module version matches that release exactly, while a pseudo-version install (@main, @<sha>) still prints unknown and -ldflags/vcs.time continue to take precedence. (#163)