Improve build process for VEXing

[mallardduck]

Before:

 → go version -m ./build/bin/prometheus-federator|head -2
./build/bin/prometheus-federator: go1.23.4
        path    command-line-arguments

After:

 → go version -m ./build/bin/prometheus-federator|head -2
./build/bin/prometheus-federator: go1.23.4
        path    github.com/rancher/prometheus-federator/cmd/prometheus-federator

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Note that in the process of removing tags to improve VEX support we noticed that tags were also preventing some code from being linted. Specifically the cmd files were excluded. After the change they are included, so these additional commits to fix those changes were necessary.