Address build-args typo in ci

[brookslogan]

E.g., here. "Warning: Unexpected input(s) 'build-args', valid inputs are ['args', 'build_args', 'error-on', 'check-dir', 'working-directory', 'upload-snapshots', 'upload-results']"

[dshemetov]

That line should be removed anyhow - it's better to build vignettes in the CI, as it acts as another sanity check on the package.