[goreleaser] Only build amd64 architecture for m3query releases

[robskillington]

What this PR does / why we need it:

Without specifying architecture goreleaser by default builds both amd64 and i386. To speed up releases this makes m3query only build amd64 like all our other binaries.

Special notes for your reviewer:

Does this PR introduce a user-facing and/or backwards incompatible change?:

NONE

Does this PR require updating code package or user-facing documentation?:

NONE

[codecov]

Codecov Report

Merging #2202 into master will decrease coverage by 0.0%.
The diff coverage is n/a.

@@           Coverage Diff            @@
##           master   #2202     +/-   ##
========================================
- Coverage    72.2%   72.2%   -0.1%     
========================================
  Files        1022    1022             
  Lines       88793   88793             
========================================
- Hits        64145   64125     -20     
- Misses      20352   20365     +13     
- Partials     4296    4303      +7     

Flag	Coverage Δ
#aggregator	82.1% <ø> (-0.1%)	⬇️
#cluster	85.2% <ø> (-0.2%)	⬇️
#collector	82.8% <ø> (ø)
#dbnode	79.0% <ø> (-0.1%)	⬇️
#m3em	74.4% <ø> (ø)
#m3ninx	72.3% <ø> (-0.1%)	⬇️
#m3nsch	51.1% <ø> (ø)
#metrics	17.6% <ø> (ø)
#msg	74.9% <ø> (ø)
#query	68.4% <ø> (ø)
#x	83.2% <ø> (-0.1%)	⬇️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 527d5f5...23ad916. Read the comment docs.

[arnikola]

lgtm