omit vcs info from build

[spencerschrock]

The detected info is interfering with the manually specified Scorecard version in the LDFLAGS. While buildvcs has been present since Go 1.18, Go 1.24 changed the behavior again. Our docker image uses Go 1.24 as of 3676bbc.

https://go.dev/doc/go1.24#go-command

The go build command now sets the main module’s version in the compiled binary based on the version control system tag and/or commit. A +dirty suffix will be appended if there are uncommitted changes. Use the -buildvcs=false flag to omit version control information from the binary.

This trickled down to the produced output:
Before this PR:

"scorecard": { 
  "version":"v0.0.0-20250218152336-6a62a1cbf280",
  "commit":"cd152cb6742c5b8f2f3d2b5193b41d9c50905198"
}

After:

"scorecard": {
  "version":"v5.1.1",
  "commit":"cd152cb6742c5b8f2f3d2b5193b41d9c50905198"
}