Bump cloud.google.com/go/datastore from 1.20.0 to 1.21.0

Bumps [cloud.google.com/go/datastore](https://github.com/googleapis/google-cloud-go) from 1.20.0 to 1.21.0.
- [Release notes](https://github.com/googleapis/google-cloud-go/releases)
- [Changelog](https://github.com/googleapis/google-cloud-go/blob/main/documentai/CHANGES.md)
- [Commits](googleapis/google-cloud-go@kms/v1.20.0...kms/v1.21.0)

---
updated-dependencies:
- dependency-name: cloud.google.com/go/datastore
  dependency-version: 1.21.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

go.mod

@@ -4,7 +4,7 @@ go 1.25.3
 
 require (
 	cloud.google.com/go/cloudtasks v1.13.7
-	cloud.google.com/go/datastore v1.20.0
+	cloud.google.com/go/datastore v1.21.0
 	cloud.google.com/go/logging v1.13.0
 	cloud.google.com/go/secretmanager v1.16.0
 	cloud.google.com/go/storage v1.57.0

go.sum

@@ -14,8 +14,8 @@ cloud.google.com/go/cloudtasks v1.13.7 h1:H2v8GEolNtMFfYzUpZBaZbydqU7drpyo99GtAg
 cloud.google.com/go/cloudtasks v1.13.7/go.mod h1:H0TThOUG+Ml34e2+ZtW6k6nt4i9KuH3nYAJ5mxh7OM4=
 cloud.google.com/go/compute/metadata v0.9.0 h1:pDUj4QMoPejqq20dK0Pg2N4yG9zIkYGdBtwLoEkH9Zs=
 cloud.google.com/go/compute/metadata v0.9.0/go.mod h1:E0bWwX5wTnLPedCKqk3pJmVgCBSM6qQI1yTBdEb3C10=
-cloud.google.com/go/datastore v1.20.0 h1:NNpXoyEqIJmZFc0ACcwBEaXnmscUpcG4NkKnbCePmiM=
-cloud.google.com/go/datastore v1.20.0/go.mod h1:uFo3e+aEpRfHgtp5pp0+6M0o147KoPaYNaPAKpfh8Ew=
+cloud.google.com/go/datastore v1.21.0 h1:dUrYq47ysCA4nM7u8kRT0WnbfXc6TzX49cP3TCwIiA0=
+cloud.google.com/go/datastore v1.21.0/go.mod h1:9l+KyAHO+YVVcdBbNQZJu8svF17Nw5sMKuFR0LYf1nY=
 cloud.google.com/go/iam v1.5.2 h1:qgFRAGEmd8z6dJ/qyEchAuL9jpswyODjA2lS+w234g8=
 cloud.google.com/go/iam v1.5.2/go.mod h1:SE1vg0N81zQqLzQEwxL2WI6yhetBdbNQuTvIKCSkUHE=
 cloud.google.com/go/logging v1.13.0 h1:7j0HgAp0B94o1YRDqiqm26w4q1rDMH7XNRU34lJXHYc=