feat: Add the Digest field to ReleaseAsset

[suzuki-shunsuke]

Close#3627

https://github.blog/changelog/2025-06-03-releases-now-expose-digests-for-release-assets/
https://docs.github.com/en/rest/releases/releases?apiVersion=2022-11-28#get-a-release

The Get a Release API returns digests of assets.
To get digests, this commit adds the field Digest and the method GetDigest to ReleaseAsset.

[suzuki-shunsuke]

Test has passed.

$ ./script/test.shtesting .ok github.com/google/go-github/v73/github	3.617s	coverage: 99.1% of statements	github.com/google/go-github/v73/test/fields coverage: 0.0% of statements? github.com/google/go-github/v73/test/integration	[no test files]testing example	github.com/google/go-github/v73/example/actionpermissions coverage: 0.0% of statements	github.com/google/go-github/v73/example/appengine coverage: 0.0% of statements	github.com/google/go-github/v73/example/basicauth coverage: 0.0% of statements	github.com/google/go-github/v73/example/codespaces/newreposecretwithxcrypto coverage: 0.0% of statements	github.com/google/go-github/v73/example/codespaces/newusersecretwithxcrypto coverage: 0.0% of statements	github.com/google/go-github/v73/example/commitpr coverage: 0.0% of statements	github.com/google/go-github/v73/example/listenvironments coverage: 0.0% of statements	github.com/google/go-github/v73/example/migrations coverage: 0.0% of statements	github.com/google/go-github/v73/example/newfilewithappauth coverage: 0.0% of statements	github.com/google/go-github/v73/example/newrepo coverage: 0.0% of statements	github.com/google/go-github/v73/example/newreposecretwithxcrypto coverage: 0.0% of statements	github.com/google/go-github/v73/example/ratelimit coverage: 0.0% of statements	github.com/google/go-github/v73/example/simple coverage: 0.0% of statements	github.com/google/go-github/v73/example/tokenauth coverage: 0.0% of statements	github.com/google/go-github/v73/example/topics coverage: 0.0% of statements	github.com/google/go-github/v73/example/verifyartifact coverage: 0.0% of statementstesting scrapeok github.com/google/go-github/scrape	1.234s	coverage: 59.4% of statements	github.com/google/go-github/scrape/example/scrape coverage: 0.0% of statementstesting toolsok tools/metadata	1.280s	coverage: 81.7% of statementstesting tools/sliceofpointersok tools/sliceofpointers	1.452s	coverage: 94.7% of statements

[suzuki-shunsuke]

I've confirmed the fix works as expected.

package main
import (
"context""encoding/json""log""os""github.com/google/go-github/v73/github""golang.org/x/oauth2"
)
funcmain() {
iferr:=run(); err!=nil {
log.Fatal(err)
}
}
funcrun() error {
ctx:=context.Background()
httpClient:=oauth2.NewClient(ctx, oauth2.StaticTokenSource(
&oauth2.Token{AccessToken: os.Getenv("GITHUB_TOKEN")},
))
client:=github.NewClient(httpClient).Repositoriesrelease, _, err:=client.GetRelease(ctx, "aquaproj", "aqua", 233010212)
iferr!=nil {
returnerr
}
encoder:=json.NewEncoder(os.Stdout)
encoder.SetIndent("", " ")
iferr:=encoder.Encode(release); err!=nil {
returnerr
}
returnnil
}

modulefoogo1.24.5require (
github.com/google/go-github/v73v73.0.0golang.org/x/oauth2v0.30.0
)
replacegithub.com/google/go-github/v73=>github.com/suzuki-shunsuke/go-github/v73v73.0.1-0.20250719051818-956a007e23farequiregithub.com/google/go-querystringv1.1.0// indirect

GITHUB_TOKEN=$(gh auth token) go run main.go

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 91.33%. Comparing base (69f5bc7) to head (956a007).
Report is 1 commits behind head on master.

Additional details and impacted files

@@ Coverage Diff @@## master #3628 +/- ##
=======================================
Coverage 91.33% 91.33% =======================================
Files 184 184 Lines 16174 16174 =======================================
Hits 14773 14773 Misses 1227 1227 Partials 174 174 

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[gmlewis]

Thank you, @suzuki-shunsuke and @alexandear!
LGTM.
Merging.