CI failing on staticcheck version

[s-kanev]

Failing on HEAD for all tip configurations (linux and macos), when trying to invoke staticcheck:

https://github.com/google/pprof/runs/4063340955

++ staticcheck github.com/google/pprof github.com/google/pprof/driver github.com/google/pprof/fuzz github.com/google/pprof/internal/binutils github.com/google/pprof/internal/driver github.com/google/pprof/internal/elfexec github.com/google/pprof/internal/graph github.com/google/pprof/internal/measurement github.com/google/pprof/internal/plugin github.com/google/pprof/internal/proftest github.com/google/pprof/internal/report github.com/google/pprof/internal/symbolizer github.com/google/pprof/internal/symbolz github.com/google/pprof/internal/transport github.com/google/pprof/profile github.com/google/pprof/third_party/d3 github.com/google/pprof/third_party/d3flamegraph github.com/google/pprof/third_party/svgpan
-: cannot import "internal/cpu" (unknown iexport format version 2), export data is newer version - update tool (compile)
-: cannot import "internal/goarch" (unknown iexport format version 2), export data is newer version - update tool (compile)
Error: Process completed with exit code 1.

It seems like a simple version issue with staticcheck -- probably because we don't use actions/setup-go@v2 in the tip configuration here and instead fetch lint tools manually.

[s-kanev]

Ah, from dominikh/go-tools#1107, the tip compiler is unsupported and not expected to work with staticcheck.

I'll just disable it in the CI then. We already do it for the latest two versions of the compiler (which are supported) anyway.