fix: vendor is not a recognized deb control field

[caarlos0]

refs #439

lintian says:

W: nfpm: unknown-field nfpm_amd64.deb Vendor

[codecov]

Codecov Report

Merging #446 (3aa1248) into main (00413e3) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             main     #446   +/-   ##
=======================================
  Coverage   65.86%   65.86%           
=======================================
  Files          16       16           
  Lines        1901     1901           
=======================================
  Hits         1252     1252           
  Misses        510      510           
  Partials      139      139           

Impacted Files	Coverage Δ
deb/deb.go	70.16% <ø> (ø)

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