Bump google.golang.org/grpc from 1.79.2 to 1.79.3 in /system-tests/tests

Bumps [google.golang.org/grpc](https://github.com/grpc/grpc-go) from 1.79.2 to 1.79.3.
- [Release notes](https://github.com/grpc/grpc-go/releases)
- [Commits](grpc/grpc-go@v1.79.2...v1.79.3)

---
updated-dependencies:
- dependency-name: google.golang.org/grpc
  dependency-version: 1.79.3
  dependency-type: direct:production
...

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

Author: dependabot[bot]

system-tests/tests/go.mod

@@ -743,7 +743,7 @@ require (
 	google.golang.org/genproto v0.0.0-20260128011058-8636f8732409 // indirect
 	google.golang.org/genproto/googleapis/api v0.0.0-20260217215200-42d3e9bedb6d // indirect
 	google.golang.org/genproto/googleapis/rpc v0.0.0-20260209200024-4cfbd4190f57 // indirect
-	google.golang.org/grpc v1.79.2
+	google.golang.org/grpc v1.79.3
 	gopkg.in/evanphx/json-patch.v4 v4.13.0 // indirect
 	gopkg.in/guregu/null.v4 v4.0.0 // indirect
 	gopkg.in/inf.v0 v0.9.1 // indirect