fix: filter noise from license checks

[dmcilvaney]

Filter out:

🚀 collectLicenses: Collecting licenses
W0604 10:03:13.741344 3396429 library.go:141] "golang.org/x/sys/unix" contains non-Go code that can't be inspected for further dependencies:
/home/damcilva/go/pkg/mod/golang.org/x/sys@v0.44.0/unix/asm_linux_amd64.s
W0604 10:03:13.741542 3396429 library.go:141] "github.com/klauspost/compress/zstd" contains non-Go code that can't be inspected for further dependencies:
/home/damcilva/go/pkg/mod/github.com/klauspost/compress@v1.18.6/zstd/fse_decoder_amd64.s
/home/damcilva/go/pkg/mod/github.com/klauspost/compress@v1.18.6/zstd/matchlen_amd64.s
/home/damcilva/go/pkg/mod/github.com/klauspost/compress@v1.18.6/zstd/seqdec_amd64.s
W0604 10:03:13.741597 3396429 library.go:141] "github.com/klauspost/compress/huff0" contains non-Go code that can't be inspected for further dependencies:
/home/damcilva/go/pkg/mod/github.com/klauspost/compress@v1.18.6/huff0/decompress_amd64.s
...

[Copilot]

Pull request overview

This PR reduces noise from go-licenses by filtering out benign “contains non-Go code that can't be inspected” glog warnings (and their continuation path lines), only surfacing remaining output when the license command fails.

Changes:

• Added reusable filtering/printing helpers in mageutil for suppressing known-benign go-licenses warning blocks.
• Updated the license check (go-licenses check) to capture combined output and print only filtered output on failure.
• Updated the license report/save paths to capture stderr, filter benign warnings, and only print remaining stderr output on failure.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 1 comment.

File	Description
magefiles/mageutil/mageutil.go	Adds FilterLicenseNoise and PrintLicenseOutput helpers to remove known-benign go-licenses warning blocks.
magefiles/magecheckfix/checkfix.go	Refactors license check/report to capture output and suppress benign warnings unless a command fails.
magefiles/magebuild/magebuild.go	Captures go-licenses save stderr to suppress benign warnings unless license collection fails.