Bump github.com/open-policy-agent/opa in /services/gateway

Bumps [github.com/open-policy-agent/opa](https://github.com/open-policy-agent/opa) from 0.28.0 to 0.43.1.
- [Release notes](https://github.com/open-policy-agent/opa/releases)
- [Changelog](https://github.com/open-policy-agent/opa/blob/main/CHANGELOG.md)
- [Commits](open-policy-agent/opa@v0.28.0...v0.43.1)

---
updated-dependencies:
- dependency-name: github.com/open-policy-agent/opa
  dependency-type: direct:production
...

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

Author: dependabot[bot]

services/gateway/go.mod

@@ -4,26 +4,22 @@ go 1.14
 
 require (
 	github.com/dgrijalva/jwt-go v3.2.0+incompatible
-	github.com/go-ini/ini v1.57.0 // indirect
 	github.com/gorilla/mux v1.8.0
 	github.com/gravitational/trace v1.1.11 // indirect
 	github.com/jinzhu/configor v1.2.1
-	github.com/jonboulle/clockwork v0.2.0 // indirect
 	github.com/joonix/log v0.0.0-20180502111528-d2d3f2f4a806
 	github.com/lestrrat-go/jwx v1.2.0
 	github.com/minio/minio-go v6.0.14+incompatible
-	github.com/mitchellh/go-homedir v1.1.0 // indirect
 	github.com/nats-io/jwt v1.0.1 // indirect
+	github.com/nats-io/nats-server/v2 v2.1.2 // indirect
 	github.com/nats-io/nats.go v1.10.0
 	github.com/nats-io/nkeys v0.2.0 // indirect
-	github.com/open-policy-agent/opa v0.28.0
-	github.com/prometheus/client_golang v1.10.0
+	github.com/open-policy-agent/opa v0.43.1
+	github.com/prometheus/client_golang v1.12.2
 	github.com/rs/cors v1.7.0
 	github.com/sirupsen/logrus v1.9.0
 	github.com/urfave/negroni v1.0.0
 	github.com/vulcand/oxy v1.3.0
-	golang.org/x/crypto v0.0.0-20201217014255-9d1352758620
-	google.golang.org/protobuf v1.25.0 // indirect
+	golang.org/x/crypto v0.0.0-20220525230936-793ad666bf5e
 	gopkg.in/h2non/gock.v1 v1.0.16
-	gopkg.in/ini.v1 v1.60.0 // indirect
 )