cmd/go: TestScript/install_cgo_excluded failures

```
#!watchflakes
default <- pkg == "cmd/go" && test == "TestScript/install_cgo_excluded"
```

Issue created automatically to collect these failures.

Example ([log](https://ci.chromium.org/b/8680713010341962961)):

=== RUN TestScript/install_cgo_excluded
=== PAUSE TestScript/install_cgo_excluded
=== CONT TestScript/install_cgo_excluded
script_test.go:141: 2026-05-26T19:50:34Z
script_test.go:143: $WORK=/home/swarming/.swarming/w/ir/x/t/cmd-go-test-410661730/tmpdir1614460497/install_cgo_excluded2887594636
script_test.go:165:
PATH=/home/swarming/.swarming/w/ir/x/t/cmd-go-test-410661730/tmpdir1614460497/testbin:/home/swarming/.swarming/w/ir/x/w/goroot/bin:/home/swarming/.swarming/w/ir/x/w/goroot/bin:/home/swarming/.swarming/w/ir/x/w/goroot/bin:/home/swarming/.swarming/w/ir/cache/tools/bin:/home/swarming/.swarming/w/ir/bbagent_utility_packages:/home/swarming/.swarming/w/ir/bbagent_utility_packages/bin:/home/swarming/.swarming/w/ir/cipd_bin_packages:/home/swarming/.swarming/w/ir/cipd_bin_packages/bin:/home/swarming/.swarming/w/ir/cache/cipd_client:/home/swarming/.swarming/w/ir/cache/cipd_client/bin:/home/swarming/.swarming/cipd_cache/bin:/sbin:/bin:/usr/sbin:/usr/bin:/usr/local/sbin:/usr/local/bin:/home/swarming/bin
HOME=/no-home
CCACHE_DISABLE=1
GOARCH=amd64
...
TMPDIR=/home/swarming/.swarming/w/ir/x/t/cmd-go-test-410661730/tmpdir1614460497/install_cgo_excluded2887594636/tmp
GOPATH=/home/swarming/.swarming/w/ir/x/t/cmd-go-test-410661730/tmpdir1614460497/install_cgo_excluded2887594636/gopath
PWD=/home/swarming/.swarming/w/ir/x/t/cmd-go-test-410661730/tmpdir1614460497/install_cgo_excluded2887594636/gopath/src

> env CGO_ENABLED=0
> ! go install cgotest
[exit status 1]
> stderr 'build constraints exclude all Go files'
script_test.go:165: FAIL: testdata/script/install_cgo_excluded.txt:4: stderr 'build constraints exclude all Go files': no match for `(?m)build constraints exclude all Go files` in stderr
--- FAIL: TestScript/install_cgo_excluded (27.09s)

— [watchflakes](https://go.dev/wiki/Watchflakes)