Replaces go install for 11 tools with direct binary/tarball downloads
from GitHub releases. Build time drops from 2+ hours to ~10 minutes
and arm64 QEMU segfaults are eliminated (no Go compilation for goreleaser).
- rootfs/root/docker/setup/05-custom.sh: add _gh_latest/_install_tar/_install_bin
helpers; download goreleaser, golangci-lint, staticcheck, gofumpt,
gotestsum, ko, air, buf, goose, gopls, govulncheck from release artifacts;
keep go install only for goimports, stringer, dlv, gops, benchstat,
wire, mockgen, protoc-gen-go, protoc-gen-go-grpc; remove -p=1 arm64
workaround (no longer needed)
rootfs/root/docker/setup/05-custom.sh