Added GHA to run go vet and go fmt checks.

[bendory]

Changes

Added GHA to run go vet and go fmt checks.

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Release Notes

NONE

[bendory]

Happily, go vet and go fmt are clean in this repo. That was not the case over in pipelines, so I'm adding this GHA here too to prevent us from losing integrity down the road.

[lcarva]

/lgtm

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