Release 0.6.7

What's Changed

• ci, Makefile: make check-readme a make target by @woodruffw in #233
• Makefile: run recursive make silently by @woodruffw in #234
• Tests: ensure consistency of transparency log response and entry by @woodruffw in #235
• Staging workflow improvements by @woodruffw in #202
• build(deps): bump sigstore from 0.6.5 to 0.6.6 in /install by @dependabot in #236
• rekor, verify: replace unstable API use by @woodruffw in #238
• rekor/client: fix result search by @woodruffw in #239
• build(deps): bump typing-extensions from 4.3.0 to 4.4.0 in /install by @dependabot in #240
• _verify: make the failure reason more detailed when rekor lookup fails by @woodruffw in #241
• _cli: add envvar defaults for most options by @woodruffw in #242
• sigstore: 0.6.7 by @woodruffw in #243

Full Changelog: v0.6.6...v0.6.7