feat: Add support for templating NFPM bindir

[caarlos0]

In NFPM configuration, allow the Bindir to also be templated.

Why is this change being made ?

I'm creating a nagios plugin . Those are deployed in the /usr/lib/nagios/plugins directory on i386 arch. And in /usr/lib64/nagios/plugins on amd64 arch.
I wasn't able to achieve such behavior with RPM generation without this patch.

With this patch applied, one can use the following configuation:

nfpms:
  - file_name_template: '{{ .ProjectName }}_{{ .Arch }}'
[...]
    bindir: '/usr/lib{{ if ne .Arch "386" }}64{{ end }}/nagios/plugins'
[...]

closes #2460

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[codecov]

Codecov Report

Merging #2466 (c2802f5) into master (7d22a32) will increase coverage by 0.01%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master    #2466      +/-   ##
==========================================
+ Coverage   83.01%   83.02%   +0.01%     
==========================================
  Files          87       87              
  Lines        6271     6275       +4     
==========================================
+ Hits         5206     5210       +4     
  Misses        915      915              
  Partials      150      150              

Impacted Files	Coverage Δ
internal/pipe/nfpm/nfpm.go	94.64% <100.00%> (+0.07%)	⬆️

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