Currently we do not set the env variables for `go list ./...` resulting
in errors like
```
build constraints exclude all Go files in
/home/runner/work/tailscale/tailscale/chirp
```
Signed-off-by: Maisem Ali <maisem@tailscale.com>
To prevent issues like #1786, run staticcheck on the primary GOOSes:
linux, mac, and windows.
Windows also has a fair amount of GOARCH-specific code.
If we ever have GOARCH staticcheck failures on other GOOSes,
we can expand the test matrix further.
This requires installing the staticcheck binary so that
we can execute it with different GOOSes.
Signed-off-by: Josh Bleecher Snyder <josharian@gmail.com>