Checksum mismatch error

[sjberman]

When using GOPROXY=direct and go mod tidy, the checksum of this repo seems to have been changed.

github.com/tsenart/vegeta/v12/lib: github.com/tsenart/vegeta/v12@v12.13.0: verifying module: checksum mismatch
	downloaded: h1:G5P3t0a/HlcqNWxJEcqRE6+LdvRKfDdg3qtR+5fTsSg=
	sum.golang.org: h1:J/UiNS3f69MkL0tsRLVUUV8uXXQZxdRUchtS+GYiSFc=

SECURITY ERROR
This download does NOT match the one reported by the checksum server.
The bits may have been replaced on the origin server, or an attacker may
have intercepted the download attempt.

This is blocking pipelines for us.

[sjberman]

@tsenart