build(deps): bump github.com/open-policy-agent/opa from 1.5.0 to 1.5.1

Bumps [github.com/open-policy-agent/opa](https://github.com/open-policy-agent/opa) from 1.5.0 to 1.5.1.
- [Release notes](https://github.com/open-policy-agent/opa/releases)
- [Changelog](https://github.com/open-policy-agent/opa/blob/main/CHANGELOG.md)
- [Commits](https://github.com/open-policy-agent/opa/compare/v1.5.0...v1.5.1)

---
updated-dependencies:
- dependency-name: github.com/open-policy-agent/opa
  dependency-version: 1.5.1
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

go.sum

@@ -863,8 +863,8 @@ github.com/onsi/gomega v1.7.1/go.mod h1:XdKZgCCFLUoM/7CFJVPcG8C1xQ1AJ0vpAezJrB7J
 github.com/onsi/gomega v1.10.1/go.mod h1:iN09h71vgCQne3DLsj+A5owkum+a2tYe+TOCB1ybHNo=
 github.com/onsi/gomega v1.37.0 h1:CdEG8g0S133B4OswTDC/5XPSzE1OeP29QOioj2PID2Y=
 github.com/onsi/gomega v1.37.0/go.mod h1:8D9+Txp43QWKhM24yyOBEdpkzN8FvJyAwecBgsU4KU0=
-github.com/open-policy-agent/opa v1.5.0 h1:npsQMUZvafCLYHofoNrZ0cSWbvoDpasvWtrHXdEvSuM=
-github.com/open-policy-agent/opa v1.5.0/go.mod h1:bYbS7u+uhTI+cxHQIpzvr5hxX0hV7urWtY+38ZtjMgk=
+github.com/open-policy-agent/opa v1.5.1 h1:LTxxBJusMVjfs67W4FoRcnMfXADIGFMzpqnfk6D08Cg=
+github.com/open-policy-agent/opa v1.5.1/go.mod h1:bYbS7u+uhTI+cxHQIpzvr5hxX0hV7urWtY+38ZtjMgk=
 github.com/opencloud-eu/go-micro-plugins/v4/store/nats-js-kv v0.0.0-20250512152754-23325793059a h1:Sakl76blJAaM6NxylVkgSzktjo2dS504iDotEFJsh3M=
 github.com/opencloud-eu/go-micro-plugins/v4/store/nats-js-kv v0.0.0-20250512152754-23325793059a/go.mod h1:pjcozWijkNPbEtX5SIQaxEW/h8VAVZYTLx+70bmB3LY=
 github.com/opencloud-eu/libre-graph-api-go v1.0.8-0.20250603072916-fa601fb14450 h1:QWn9G2f1R/EbyZSbkjtd9jqNq9X0NIphmmD4KYLNZtA=